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UBC Theses and Dissertations

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UBC Theses and Dissertations

Rhacomitrium heterostichum complex in British Columbia Banu, Khurshida 1969

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The R h a c o m i t r i u m h e t e r o s t i c h u m complex i n B r i t i s h C o l u m b i a by KHURSHIDA BANU B . S c , Dacca U n i v e r s i t y , E a s t P a k i s t a n M . S c , Dacca U n i v e r s i t y , E a s t P a k i s t a n A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n t h e Department o f BOTANY We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o t h e r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA November, 1969 In presenting th i s thes i s in pa r t i a l f u l f i lment o f the requirements fo r an advanced degree at the Un ivers i ty of B r i t i s h Columbia, I agree that the L ibrary sha l l make i t f r ee l y ava i l ab le for reference and study. I fu r ther agree tha permission for extensive copying of th i s thes i s for scho la r l y purposes may be granted by the Head of my Department or by his representat ives. It i s understood that copying or pub l i ca t ion of th i s thes i s f o r f i nanc ia l gain sha l l not be allowed without my wr i t ten permission. Department of J B P T A N y The Univers i ty of B r i t i s h Columbia Vancouver 8, Canada Date 1 7 H i ) s i o V & i v i b -<^ , i1£>1 i ABSTRACT The R h a c o r n i t r i u m h e t e r o s t i c h u m complex i n B r i t i s h C o l u m b i a c o n s i s t s o f f o u r s p e c i e s and f i v e v a r i e t i e s : Ro "laxum", R. h e t e r o s t i c h u m , R„ h e t e r o s t i c h u m v a r . a f f i n e , R. s u d e t i c u m , R. s u d e t i c u m v a n m a c o u n i i , R. b r e v i p e s , Ro b r e v i p e s v a r . " l a e v i s " , v a r . "eramulosum" and v a r . " m i c r o c a r p i f o r m i s " . W i t h i n each o f t h e s e t a x a minor v a r i a t i o n s o c c u r o R. s u d e t i c u m t e n d s t o be c o n f i n e d t o s u b - a l p i n e and a l p i n e l o c a l i t i e s and R. h e t e r o s t i c h u m t o l o w e r e l e v a t i o n s , w h i l e R. "laxum" and R. b r e v i p e s show no a l t i t u d i n a l l i m i t -a t i o n s . There appears t o be a p o s i t i v e c o r r e l a t i o n between n a t u r e o f b r a n c h i n g and d e t a i l s o f l e a f apex s t r u c t u r e t o m o i s t u r e c o n d i t i o n s : s h o r t b r a n c h e s , a b b r e v i a t e d h a i r p o i n t and s h o r t e r l e a f c e l l s i n t h e l e a f apex b e i n g commoner i n specimens o f wet s i t e s t h a n i n specimens o f d r y s i t e s . E x p e r i m e n t a l e v i d e n c e i s needed t o d e t e r m i n e p h e n o t y p i c p l a s t i c i t y i n t h e s e c h a r a c t e r s , s i n c e t h e y a r e w i d e l y used t o d i s t i n g u i s h among t h e v a r i o u s t a x a o f t h e R. h e t e r o s t i c h u m complex„ i i i TABLE OF CONTENTS PAGE. A b s t r a c t i Acknowledgement i i T a b l e o f C o n t e n t s i i i L i s t o f T a b l e and P l a t e s i v INTRODUCTION 1 TAXONOMIC TREATMENT 8 I n t r o d u c t i o n 8 D e s c r i p t i o n o f t h e genus 8 E c o l o g y 9 D i s t r i b u t i o n 9 R, "laxum" 11 R„ h e t e r o s t i c h u m 16 R. h e t e r o s t i c h u m v a r . a f f i n e 19' R. s u d e t i c u m 2 2 R. s u d e t i c u m v a r . m a c o u n i i 26 R. b r e v i p e s 29 R. b r e v i p e s v a r . " l a e v i s " 32 R„ b r e v i p e s var: "eramulosum" 34 R. b r e v i p e s v a r . " m i c r o c a r p i f o r m i s " 36 Key t o t h e R h a c o m i t r i u m h e t e r o s t i c h u m complex i n B r i t i s h C o l u m b i a 40 DISCUSSION 44 BIBLIOGRAPHY 4 7 APPENDIX i v LIST OF TABLE AND PLATES TABLE. I PLATES I X X I I PAGE 42 APPENDIX X I X xx; XXI X X I I I - I I I R. "laxum" IV & V R 0 h e t e r o s t i c h u m VI R. R. h e t e r o s t i c h u m & h e t e r o s t i c h u m v a r . a f f i n e V I I Ro h e t e r o s t i c h u m v a r . a f f i n e V I I I & IX R. s u d e t i c u m X R. s u d e t i c u m v a r . m a c o u n i i & R. s u d e t i c u m X I & X I I R. b r e v i p e s X I I I R. b r e v i p e s & R. b r e v i p e s v a r . "m i c r o c a r p : XIV R. b r e v i p e s v a r " l a e v i s " XV Ro Ro b r e v i p e s v a r . "eramulosum" & b r e v i p e s v a r . " m i c r o c a r p i f o r m i s " XVI R. b r e v i p e s v a r . " m i c r o c a r p i f o r m i s " X V I I Leaves o f R. "laxum" X V I I I Leaves o f R, h e t e r o s t i c h u m & Ro h e t e r o s t i c h u m v a r . a f f i n e Leaves o f R. s u d e t i c u m Leaves o f R. s u d e t i c u m v a r . m a c o u n i i L eaves o f R. b r e v i p e s ' & R „ b r e v i p e s v a r . " l a e v i s " L e aves o f R. b r e v i p e s v a r . "eramulosum" & R. b r e v i p e s v a r . " m i c r o c a r p i f o r m i s " • ACKNOWLEDGEMENT The a u t h o r g r a t e f u l l y acknowledges t h e g u i d a n c e , a d v i c e and encouragement e x t e n d e d t o h e r by Dr. W..B. S c h o f i e l d t h r o u g h o u t t h e progress" o f t h i s i n v e s t i g a t i o n . S i n c e r e t h a n k s go t o P r o f e s s o r G.H.N. Towers, Dr. G. Hughes and Dr. J.R. S t e i n f o r t h e i r ; c o n t i n u e d i n t e r e s t and a d v i c e d u r i n g t h e s t u d y . The a u t h o r w i s h e s t o thank Dr. R.R. I r e l a n d , C u r a t o r o f t h e B r y o l o g i c a l H e r b a r i u m , N a t i o n a l Museum o f Canada who s e n t on l o a n s p e c i m e n s , p a r t i c u l a r l y t y p e specimens; Mr. V.L. Bourne f o r a s s i s t a n c e i n p h o t o m i c r o g r a p h y and Dr. Q.A.. F a t t a h f o r encouragement and h e l p t h r o u g h o u t h e r s t u d i e s . Acknowledgement i s e x p r e s s e d t o t h e E d u c a t i o n Department, Government o f E a s t P a k i s t a n , f o r g r a n t i n g s t u d y l e a v e . N a t i o n a l R e s e a r c h C o u n c i l , Canada, c o n t r i b u t e d f i n a n c i a l a s s i s t a n c e t h r o u g h a g r a n t awarded t o Dr. W.B. S c h o f i e l d . 1 INTRODUCTION R h a c o m i t r i u m . a genus i n t h e f a m i l y Grimmiaceae ( M u s c i ) , was d e s c r i b e d by B r i d e l i n 1819 t o accommodate a number o f s p e c i e s p r e v i o u s l y i n c l u d e d i n Trichostomum Hedw. The genus Trichostomum was so b r o a d l y i n t e r p r e t e d t h a t i t i n c l u d e d t a x a b e l o n g i n g t o t h e f a m i l i e s Grimmiaceae, P o t t i a c e a e and D i t r i c h a c e a e . I n e r e c t i n g t h e genus B r i d e l gave g r e a t e r prominence t o gametophyte c h a r a c t e r s t h a n had p r e v i o u s w o r k e r s , b a s i n g t h e genus l a r g e l y on t h e v e r y c h a r a c t e r i s t i c s i n u o u s n a t u r e o f t h e l e a f c e l l w a l l s . T h i s t y p e o f a r e o l a t i o n i s v i r t u a l l y u n i q u e t o R h a c o m i t r i u m and s e p a r a t e s i t c l e a r l y from a l l o t h e r g e n e r a e x c e p t t h e c l o s e l y r e l a t e d Grimmia. R h a c o m i t r i u m c o n t a i n s s e v e n t y f i v e s p e c i e s (Van d e r W i j k , Margadant and F l o r s c h u t z , 196 7) d i s t r i b u t e d t h r o u g h o u t t h e w o r l d , e l e v e n o f w h i c h o c c u r i n N o r t h A m e r i c a (Crum, S t e e r e and A n d e r s o n , 1965). R h a c o m i t r i u m h e t e r o s t i c h u m i s one o f t h e mos~t v a r i a b l e s p e c i e s i n t h e genus p o s s e s s i n g many i l l - d e f i n e d f o r m s , t h u s t h e s p e c i e s has f r e q u e n t l y been t r e a t e d v e r y b r o a d l y as t h e "R h a c o m i t r i u m h e t e r o s t i c h u m complex". Most r e p r e s e n t a t i v e s o f t h i s complex grow on r o c k s o r sometimes on e a r t h i n mountainous r e g i o n s , p a r t i c u l a r l y i n t e m p e r a t e c l i m a t e s o f t h e N o r t h e r n Hemisphere. T a x o n o m i s t s have f r e q u e n t l y f a c e d t h e problem o f d e f i n i n g and c o r r e l a t i n g t h e c h a r a c t e r s f o u n d i n t h e R. h e t e r o s t i c h u m complex ( D i x o n , 1924; P e r s s o n , 1947; 2 Nyholm, 1956). They have r e c o g n i z e d t h i s v a r i a b i l i t y i n d i f f e r e n t ways. T h e i r d e c i s i o n s have been based on m o r p h o l o g i c a l and a n a t o m i c a l s t u d i e s o f h e r b a r i u m specimens as w e l l as e x p e r i e n c e w i t h l i v i n g p l a n t s i n t h e f i e l d . D i x o n (1896) s t a t e d t h a t " R h a c o m i t r i u m h e t e r o s t i c h u m i s o u r most v a r i a b l e s p e c i e s and t h e m u l t i p l e forms a r e so i n c o n s t a n t and so i l l - d e f i n e d as a l m o s t t o d e f y c l a s s i f i c a t i o n . They depend c h i e f l y on t h e mode o f r a m i f i c a t i o n , t h e r e l a t i v e l e n g t h , o r absence, o f t h e h a i r p o i n t , t h e v a r y i n g a c u t e n e s s o f t h e l e a v e s , and t h e f o r m , s i z e and t e x t u r e o f t h e c a p s u l e . T here appears t o be l i t t l e o r no c o r r e l a t i o n between t h e s e c h a r a c t e r s and i t i s , t h e r e f o r e , u n s a f e t o found even v a r i e t i e s on them." P e r s s o n (1947) s t a t e d t h a t t h e " H e t e r o s t i c h u m group o f t h e genus R h a c o m i t r i u m i s everywhere a r a t h e r c r i t i c a l one and e s p e c i a l l y on t h e P a c i f i c c o a s t o f N o r t h A m e r i c a . " He examined some o f t h e A l a s k a n - Y u k o n h e t e r o s t i c h u m group and o b s e r v e d t h a t t h e l e a f c e l l s g e n e r a l l y were c l e a r l y p a p i l l o s e , a f e a t u r e n o t p r e s e n t i n European m a t e r i a l . B e s i d e s t h i s c h a r a c t e r t h e specimens d i f f e r e d from European R. h e t e r o s t i c h u m i n h a v i n g t h e upper c e l l s o f t h e l e a v e s o f t h e same form as by R. m i c r o c a r p o n (Hedw.) B r i d . (R. ramulosum L i n d b . ) i . e . , pronounced e l o n g a t e , and n o t i s o d i a m e t r i c a l ' . as i n R. h e t e r o s t i c h u m . I n c a p s u l e shape, t h e specimens were most s i m i l a r t o R. h e t e r o s t i c h u m . Summarizing t h i s , he c o n c l u d e d t h a t " t h i s common A l a s k a n R h a c o m i t r i u m had c h a r a c t e r s o f b o t h R. h e t e r o s t i c h u m (most r e l a t e d ) , R. m i c r o c a r p o n and R. s u d e t i c u m 3 ( o f t e n g i v e n as a., v a r i e t y o r s u b s p e c i e s o f R. h e t e r o s t i c h u m ) b u t b e s i d e s had a l s o i t s . own i m p o r t a n t c h a r a c t e r : t h e p a p i l l o s e l e a f c e l l s , " J ones (1933) l i s t s s e v e r a l v a r i e t i e s f o r R, h e t e r o s t i c h u m v a r . a f f i n e ( S ' c h l e i c h ) <!!„ J e n s , v a r . a f f i n e f . obtusum (sm.) Moenk v a r . q r a c i l e s c e n s B.S..G. v a r . s u d e t i c u m (Funck) Jones v a r . s u d e t i c u m f . o c c i d e n t a l e (Ren. & Card.) Jones v a r . m a c o u n i i ( K i n d b . ) Jones v a r . ramulosum ( L i n d b . ) Jones Jones c o n c l u d e d t h a t , w i t h t h e p o s s i b l e e x c e p t i o n o f Grimmia a p o c a r p a Hedw. and G. t r i c h o p h y 1 1 a Grev., R. h e t e r o s t i c h u m s e n s . l a t . p o s s e s s e s t h e most v a r i a b l e s p e c i e s i n t h e Grimmiaceae. A n d e r s o n (1958) s t a t e d t h a t i n s p i t e o f t h e wide c h o i c e o f e p i t h e t s a v a i l a b l e w i t h i n t h i s complex, I am u n a b l e t o f i n d s a t i s f a c t o r y names f o r v a r i a t i o n s f r om N o r t h C a r o l i n a . " He o b s e r v e d many specimens w h i c h e x h i b i t e d c o m p l e t e i n t e r g r a d a t i o n o f d i f f e r e n t c h a r a c t e r s . The p l a n t s o f t h e R h a c o m i t r i u m h e t e r o s t i c h u m complex a r e v e r y d i f f i c u l t t o d e t e r m i n e . On h a b i t sometime t h e r e i s a r e m a r k a b l e r e s e m b l a n c e t o o t h e r s p e c i e s o f t h e genus. E° h e t e r o s t i c h u m i n i t s mode o f growth i s sometimes e r e c t and no t u n l i k e a Grimmia, such as Grimmia t r i c h o p h y l l a o r G. d e c i p i e n s ( S c h u l t z ) L i n d b . ; R. s u d e t i c u m i s q u i t e o f t e n m i s t a k e n as Grimmia i n t h e f i e l d . 4 O f t e n p l a n t s w i t h somewhat s i m i l a r c h a r a c t e r s ( e . g . upper l e a f c e l l s , n a t u r e o f m a r g i n , c a p s u l e shape, e t c . ) a r e v e r y d i f f e r e n t i n h a b i t . C o l o u r and b r a n c h i n g p a t t e r n s o f t h e gametophyte a r e h i g h l y v a r i a b l e . Thus forms w i t h e l o n g a t e d upper l e a f c e l l s a l s o p o s s e s s a most w i d e l y d i f f e r e n t form o f c a p s u l e and v a r y i n g d e g r e e s o f ro b u s t n e s s " and b r a n c h i n g . I t i s a l s o n o t uncommon t o f i n d p l a n t s w i t h t h e m a j o r i t y o f stems h a v i n g numerous s h o r t l a t e r a l b r a n c h e s and o t h e r s c o m p l e t e l y l a c k i n g s h o r t l a t e r a l b r a n c h e s . The upper c e l l s o f t h e l e a f a r e sometimes h i g h l y v a r i a b l e . W h i l e i n most l e a v e s t h e upper c e l l s a r e r o u n d , i n some c a s e s r e c t a n g u l a r c e l l s dominate o r a r e sometimes mixed w i t h round c e l l s . Sometimes i n a s i n g l e p l a n t t h e r e may be many l e a v e s where t h e upper c e l l s a r e e l o n g a t e d w h i l e o t h e r s have t h e upper c e l l s e n t i r e l y r e c t a n g u l a r o r mixed w i t h round c e l l s . I t i s p o s s i b l e t h a t t h e n a t u r e o f t h e h a i r p o i n t and t h e shape o f t h e c e l l s i n t h e upper p a r t o f t h e l e a f a r e r e l a t e d t o t h e wetness o f t h e h a b i t a t . Kawai (1965) i n h i s s t u d y o f Grimmia, n o t e d t h a t i n G. a p o c a r p a Hedw. i n wet p l a c e s c e l l s o f t h e l e a f e s p e c i a l l y a t t h e apex a r e s h o r t , h y a l i n e p o i n t i s u s u a l l y n o t found and i n d e n t i o n s a r e obscure, o r sometimes even a b s e n t , b u t i n d r y p l a c e s t h e l e a f c e l l s t e n d t o be l o n g , h y a l i n e p o i n t and i n d e n t i o n s become c o n s p i c u o u s . A s i m i l a r c o r r e l a t i o n has been n o t e d i n R h a c o m i t r i u m , p a r t i c u l a r l y i n t h e R. h e t e r o s t i c h u m complex. I n some c a s e s p l a n t s grow i n s e a s o n a l l y wet h a b i t a t s and a c t i v e growth o f t h e p l a n t i s c o n f i n e d t o t h e time t h a t 5 m o i s t u r e - i s a v a i l a b l e ( l a r g e l y autumn t o s p r i n g ) w h i l e d u r i n g t h e r e m a i n d e r of t h e y e a r t h e h a b i t a t i s d r y and t h e p l a n t d e s i c c a t e d . E x p e r i m e n t a l s t u d i e s need t o be c o n d u c t e d i n o r d e r t o s o l v e t h i s p r o b l e m . I t i s p o s s i b l e t h a t such s t u d i e s would c o n s i d e r a b l y c l a r i f y t h e n a t u r e o f t h e s t r u c t u r a l d i v e r s i t y w i t h i n t h i s s p e c i e s ; complex, though t h e y would r e q u i r e a s e v e r a l y e a r s ' d u r a t i o n t o d e t e r m i n e whether r e p e a t e d e n v i r o n -m e n t a l changes c o n s i s t e n t l y p r o d u c e d t h e same m o r p h o l o g i c a l r e s p o n s e s i n t h e gametophyte. The main o b j e c t o f t h e p r e s e n t i n v e s t i g a t i o n i s t w o - f o l d : (1) t o d e t e r m i n e t h e e x t e n t o f v a r i a b i l i t y w i t h i n t h e s p e c i e s complex i n B r i t i s h C o l u m b i a and (2) t o f i n d o u t whether o r n o t t h e r e i s a s u f f i c i e n t c o r r e l a t i o n between d i f f e r e n t c h a r a c t e r i s t i c s t o d e l i m i t s u b - s p e c i f i c t a x a . I n f o r m a t i o n was d e r i v e d from b o t h g r o s s morphology and d e t a i l e d anatomy, p a r t i c u l a r l y o f t h e l e a f . I n v e s t i g a t i o n s were c a r r i e d o u t on h e r b a r i u m specimens c o l l e c t e d i n B r i t i s h C o l u m b i a and compared w i t h European s p e c i m e n s . I t was from European m a t e r i a l t h a t t h e s p e c i e s complex was f i r s t r e c o g n i z e d . N o r t h A m e r i c a n b r y o l o g i s t s have compared A m e r i c a n specimens w i t h t h o s e from E u r o p e , and a t t e m p t e d t o f i t t h e specimens i n t o t h e c i r c u m s c r i p -t i o n o f t h e European s p e c i e s . I n c a s e s where t h e d i f f e r e n c e s were c o n s i d e r e d t o o marked, new t a x a were d e s c r i b e d t o accommodate them. Because o f t h e c o n s i d e r a b l e v a r i a b i l i t y w i t h i n t h e R. h e t e r o s t i c h u m complex, t h i s had l e d t o a g r e a t i n f l a t i o n o f 6 names, each a c c e p t e d t a x o n i n N o r t h A m e r i c a b e i n g accompanied by a v a s t a r r a y o f synonyms. D e t a i l e d a t t e n t i o n was g i v e n t o b r a n c h i n g p a t t e r n ; s i z e and shape o f l e a v e s , l e a f a r e o l a t i o n , anatomy o f l e a v e s , n a t u r e o f s t r a t i f i c a t i o n o f t h e l e a f m a r g i n , l a m i n a and c o s t a ; l e n g t h and n a t u r e ( t w i s t i n g and p a p i l l o s i t y ) o f s e t a ; shape, s i z e and n a t u r e o f t h e c a p s u l e ; c h a r a c t e r i s t i c s o f t h e p e r i s t o m e t e e t h ; e x o t h e c i a l c e l l s ; p r e s e n c e and number o f s t o m a t a ; n a t u r e and shape o f a n n u l u s and o p e r c u l u m ; and shape, n a t u r e and s i z e o f s p o r e s . D i a g n o s t i c c h a r a c t e r s used i n t h e c o n s t r u c t i o n o f k eys i n manuals were c a r e f u l l y examined. I t was f o u n d t h a t mounting m a t e r i a l i n Hoyer*s s o l u t i o n ( A n d e r s o n , 1954) gave g r e a t e r c l a r i t y t o t h e c e l l u l a r d e t a i l s t h a n w a t e r mounting. A l t h o u g h t h i s i n v o l v e s a g r e a t e r amount o f work, t h e r e s u l t i n g c l a r i t y makes d e t e r m i n a t i o n s more r e l i a b l e and i t l e a v e s permanent r e f e r e n c e s l i d e s o f t h e m a t e r i a l s t u d i e d . The key t o t h e B r i t i s h C o l u m b i a t a x a (page 40) i s by no means i d e a l . Many a t y p i c a l specimens s i m p l y w i l l n o t f i t i n t o a k e y , u n l e s s i t i s made e x t r e m e l y l o n g and cumbersome. I have t r i e d t o make t h e key as' r e l i a b l e as p o s s i b l e . The k e y s h o u l d , however, produce r e l i a b l e d e t e r m i n a t i o n s f o r t h e m a j o r i t y o f t h e s p e c i m e n s . I t can be p e r f e c t e d o n l y a f t e r c o n s i d e r a b l e f u r t h e r u s e . F o r a number o f r e a s o n s i t was n o t p o s s i b l e t o b o r row t y p e s p e c i m e n s . I n some c a s e s t h e t y p e specimen c o u l d 7 n o t be l o c a t e d ; i n some c a s e s i t may have d i s a p p e a r e d . S i n c e t h e t y p e d e s c r i p t i o n s are f r e q u e n t l y i n a d e q u a t e , t h e e v a l u a -t i o n o f t h e s e t a x a i s v i r t u a l l y i m p o s s i b l e w i t h o u t e x a m i n a t i o n o f a t y p e s p e c i m e n . Due t o u n a v a i l a b i l i t y o f some o f t h e l i t e r a t u r e , p l a n t s f rom B r i t i s h C o l u m b i a c o u l d not always be compared w i t h t y p e d e s c r i p t i o n s . Thus a number o f t h e t a x a a r e t e n t a t i v e l y g i v e n t h e names t h a t seem t o b e s t a p p l y t o them. To o t h e r s , f o r w h i c h no a v a i l a b l e name seems s a t i s f a c t o r y , a p r o v i s i o n a l d e s i g n a t i o n i s g i v e n . I n some c a s e s , s h o u l d t h e a s s u m p t i o n s made i n t h i s t h e s i s p r o v e v a l i d , new taxa. w i l l need t o be c a r e f u l l y d e s c r i b e d and i l l u s t r a t e d . Such s h o u l d n o t be done, however, u n t i l a w i d e r s u r v e y i s made o f t h e e n t i r e R. h e t e r o s t i c h u m complex. A l l specimens c i t e d , u n l e s s n o t e d o t h e r w i s e , a r e from t h e B r y o p h y t e H e r b a r i u m , U n i v e r s i t y o f B r i t i s h C o l u m b i a (UBC). Specimens c i t e d o n l y by number a r e t h o s e o f W. B. S c h o f i e l d . Specimens from t h e h e r b a r i u m o f t h e N a t i o n a l Museum o f Canada a r e c i t e d as CAN. 8 TAXONOMIC TREATMENT The genus R h a c o m i t r i u m was f i r s t d e s c r i b e d by B r i d e l (1819) i n M a n t i s s a Muscorum. R h a c o m i t r i u m i s r e l a t e d t o Grimmia t h r o u g h t h e sub-genus D r y p t o d o n . The most d i s t i n c t i v e g e n e r i c c h a r a c t e r s which s e p a r a t e i t f rom Grimmia a r e t h e p e c u l i a r b a s a l a r e o l a t i o n o f t h e lower t h i r d o f t h e l a m i n a , t h e d e e p l y c l e f t p e r i s t o m e , and t h e s u b u l a t e o p e r c u l u m . I n R'.. p a t e n s (Hedw. ) Hueben, t h e n a t u r e o f t h e h a b i t and l e a f anatomy would p l a c e t h i s s p e c i e s i n t h e genus Grimmia, i n w h i c h i t i s p l a c e d by many European a u t h o r s (Nyholm, 1957; de S l o o v e r & Demaret, 1968). The p e r i s t o m e , however, i s c h a r a c t e r i s t i c o f R h a c o m i t r i u m . I n o t h e r s p e c i e s o f t h e sub-genus D r y p t o d o n , however, more c h a r a c t e r s a r e i n common w i t h R h a c o m i t r i u m t h a n w i t h Grimmia. U n f o r t u n a t e l y no t y p e s p e c i e s has been s e l e c t e d . D e s c r i p t i o n o f t h e genus: R h a c o m i t r i u m B r i d . Mant. Muse. 78, 1819. Gametophytes r o b u s t , m o s t l y r u p e s - t r a l , u s u a l l y l o o s e l y and w i d e l y c a e s p i t o s e , y e l l o w i s h o r b l a c k i s h g r e e n ; stems s p r e a d i n g , b e a r i n g r h i z o i d s o n l y a t t h e b a s e , l e a f y t h r o u g h o u t , o f t e n w i t h numerous s h o r t l a t e r a l b r a n c h l e t s ; c e n t r a l c y l i n d e r a b s e n t , l e a v e s numerous, i m b r i c a t e d when d r y , m o s t l y l a n c e o l a t e , acuminate o r o b t u s e , o f t e n w i t h h y a l i n e h a i r p o i n t s c o n s i s t i n g o f l i n e a r , n o n - c h l o r o p h y H o s e c e l l s ; c o s t a c o m p l e t e , u s u a l l y b r o a d and f l a t , homogeneous, s i n g l e , u s u a l l y p e r c u r r e n t o r s l i g h t l y s u b - p e r c u r r e n t , l e a f m a r gins 9 sometimes b i s t r a t o s e , o r r e v o l u t e , u s u a l l y e n t i r e e x c e p t on t h e t e r m i n a l h y a l i n e p o r t i o n , o c c a s i o n a l l y d e n t i c u l a t e , l e a f c e l l s sometime p a p i l l o s e , u s u a l l y more o r l e s s i n c r a s s a t e , t h e u pper ones m o s t l y s m a l l and r o u n d i s h q u a d r a t e o r somewhat e l o n g a t e d , t h e b a s a l c e l l s l i n e a r o r r e c t a n g u l a r , u s u a l l y n o d u l o s e o r s i n u o s e , seldom e n t i r e ; d i o e c i o u s ; a n t h e r i d i a and a r c h e g o n i a t e r m i n a l on t h e stem and on s h o r t l a t e r a l b r a n c h -l e t s . Sporophyte!:. s e t a l o n g , s t r a i g h t o r a r c u a t e , u s u a l l y t w i s t e d t o t h e r i g h t ( w i t h t h e e x c e p t i o n o f t h r e e s p e c i e s ) ; u s u a l l y smooth, c a p s u l e e r e c t , e x s e r t e d , o v o i d o r e l l i p s o i d o r c y l i n d r i c a l , narrow mouthed, smooth; s t o m a t a p r e s e n t a t t h e base o f t h e c a p s u l e ; a n n u l u s p r e s e n t ; c a l y p t r a n o n - p l i c a t e , m i t r a t e , o f t e n p a p i l l o s e a t t h e apex, u s u a l l y l o n g - b e a k e d ; o p e r c u l u m c o n i c a l , l o n g - b e a k e d ; p e r i s t o m e p r e s e n t , s i n g l e ; t e e t h 16, u n i t e d a t t h e b a s e , but d e e p l y c l e f t i n t o 2-3 l i n e a r d i v i s i o n s , t r a b e c u l a t e , b a s a l membrane no t e x t e n d i n g beyond t h e a n n u l u s ; s p o r e s 0.8 - 35 /u i n d i a m e t e r . S p o r o p h y t e s g e n e r a l l y m a t u r i n g i n s p r i n g , commonly p r o d u c e d i n most s p e c i e s , E c o l o g y : E s s e n t i a l l y r u p e s t r a l on a c i d i c s u b s t r a t a ; most s p e c i e s e s s e n t i a l l y x e r o p h y t e s and t o l e r a n t o f p e r e n n i a l d e s i c c a t i o n ; some t o l e r a n t o f wet s i t u a t i o n s , b u t none e s s e n t i a l l y a q u a t i c . G e o g r a p h i c d i s t r i b u t i o n ; E s s e n t i a l l y c o s m o p o l i t a n , b u t most s p e c i e s c o n f i n e d t o t e m p e r a t e and a r c t i c c l i m a t e s ; i n t r o p i c a l l a t i t u d e s c o n f i n e d t o t h e m o u n t a i n s ; c i r c u m p o l a r 10 t h r o u g h o u t t h e N o r t h e r n Hemisphere i n E u r a s i a and N o r t h A m e r i c a ; i n t h e S o u t h e r n Hemisphere s c a t t e r e d i n South A m e r i c a , A u s t r a l a s i a , and A f r i c a ; i n f r e q u e n t i n t h e P a c i f i c I s l a n d s . 11 R h a c o m i t r i u m - " l a x u m " n. sp. Gametophytes g r e y i s h g r e e n t o dark brown; stems 5 - 1 6 cm l o n g , w i t h few o r no e l o n g a t e d b r a n c h e s ( i f p r e s e n t , about 1 - 6 cm l o n g ) , s h o r t t u f t - l i k e l a t e r a l b r a n c h l e t s none ( P I . I , f i g . 1 & 2 ) ; r h i z p i d s r e d d i s h brown, smooth, b r a n c h e d o r u n branched, o u t e r w a l l t h i c k , c r o s s " w a l l o b l i q u e ; stem d e n s e l y c o v e r e d w i t h l e a v e s ; l e a v e s l o o s e l y i m b r i c a t e t o d i v e r g e n t when d r y ( P I . I , f i g . 1 & 2 ) , w e l l s p r e a d i n g when wet, l a n c e o l a t e f r om a b r o a d b a s e , a c u m i n a t e , up t o 6.2 mm l o n g , u s u a l l y about 5 mm i n c l u d i n g 0.5 - 2.7 mm l o n g h y a l i n e p o i n t ( P I . X V I I , f i g . 1-4) wh i c h i s u s u a l l y t o o t h e d o n l y on t h e m a r g i n o r w i t h v e r y few weak t e e t h on t h e s u r f a c e as w e l l , n o t p a p i l l o s e ( P I . I , f i g . 3 ) ; upper l e a f c e l l s e l o n g a t e d , n a r r o w , about 18 - 40 /u : 2.5 AX ( P I . I , f i g . 7 ) ; lo w e r c e l l s about 24 - 40 /u : 2.5 /u, a l l c e l l w a l l s ' s i n u o s e ( P I . I , f i g . 4 ) , a p p e a r i n g w e a k l y p a p i l l o s e because o f uneven t h i c k e n i n g o f t h e s i n u o s e c e l l w a l l ; m a r g i n o f t h e l e a f e n t i r e o r a p p e a r i n g somewhat p a p i l l o s e i n t h e upper p o r t i o n , and e n t i r e downward, u n i s t r a t o s e t h r o u g h o u t ( P I . I I , f i g . 1, 2, 5 & 8) o r o c c a s i o n -a l l y i r r e g u l a r l y b i s t r a t o s e t oward t h e m i d d l e p o r t i o n o f t h e l e a f ( P I . I I , f i g . 7 ) , r e v o l u t e e i t h e r on one ma r g i n o r b o t h ( P I . X V I I , f i g . 1-4), u s u a l l y one s i d e more s t r o n g l y r e v o l u t e t h a n t h e o t h e r , n o t o r up t o t h e apex; c o s t a f l a t i n t h e l o w e r p o r t i o n b u t d i s t i n c t l y 2 - r i d g e d i n t h e upper p o r t i o n ( P I . I , f i g . 6 ) , e x t e n d i n g f a r i n t o t h e h y a l i n e p o i n t , 2 - 4 s t r a t o s e i n c r o s s s e c t i o n , 70 - 90 /u w i d e , u s u a l l y c e l l s i n t h e upper row a r e l a r g e r t h a n t h e l o w e r row o r more o r l e s s 12 s i m i l a r i n s i z e ( P I . I I , f i g . 1-5 & 8 ) ; d i o e c i o u s ; p e r i c h a e t i a l l e a v e s much t h i n n e r and b r o a d e r , c e l l s m o s t l y h y a l i n e , w i t h o r w i t h o u t h y a l i n e p o i n t . S p o r o p h y t e : s e t a u s u a l l y 4 - 5 mm l o n g , r a r e l y as s h o r t as 2.5 mm o r up t o 8.5 mm, c o r k s c r e w t w i s t e d t o t h e r i g h t , smooth; c a p s u l e e r e c t , e l l i p s o i d a l o r c y l i n d r i c a l , 1.5 - 2.8 mm l o n g and 0.6 - 0.9 mm b r o a d ( P I . I , f i g . 5 ) ; upper e x o t h e c i a l c e l l s n a r r o w , n e a r l y t r a n s v e r s e l y r e c t a n g u l a r ( P I . I l l , f i g . 2 ) , brown, median c e l l s r e c t a n g u l a r t o e l o n g a t e ( P I . I l l , f i g . 4 ) , l o w e r c e l l s r o u n d o r r e c t a n g u l a r w i t h 10 - 16 phaneropore s t o m a t a ( P I . I I , f i g . 3 ) ; o p e r c u l u m r o s t r a t e , about 0.8 mm l o n g , beak u s u a l l y s t r a i g h t , sometimes o b l i q u e , smooth; a n n u l u s 2 - 3 rows o f g o l d e n brown c e l l s ( P I . I I , f i g . 6 ) ; p e r i s t o m e t e e t h b r o w n i s h y e l l o w , 0.4 mm l o n g , p a p i l l o s e ( P I . I l l , f i g . 1 ) , f o r k e d , f o r k s j o i n e d o r f r e e , t r a n s v e r s e band n o t p r o m i n e n t , m o s t l y n o t s w o l l e n on t h e m a r g i n ( P I . I l l , f i g . 3 ) ; c a l y p t r a c o n i c a l , n o t p a p i l l o s e a t apex; 5 - 8 l a c e r a t i o n s a t t h e b a s e , 1.2 -.1.8 mm l o n g ; s p o r e s r o u n d , g r a n u l a r , g r e e n i s h y e l l o w , , 12 - 13 AX i n d i a m e t e r ( P I . I I , f i g . 4 ) . S p o r o p h y t e m a t u r i n g l a t e s p r i n g t o summer. H a b i t a t : On d r y , exposed o r shaded r o c k s o r humid, wet c l i f f , l a r g e l y a t l o w e r e l e v a t i o n s . Specimens examined: Queen C h a r l o t t e I s l a n d s : Dawson I n l e t , Graham I s l a n d , 33438; S c h o f i e l d & Vaarama, 24647; Anna I n l e t , Moresby I s l a n d , S c h o f i e l d & Vaarama 24292; W e l l s Cove, S. W. Moresby I s l a n d 13 31700; C h a a t l I s l a n d , S c h o f i e l d & Boas 18760; T a k a k i a L a k e , Moresby I s l a n d , 24898; B i g s b y I n l e t , Moresby I s l a n d , S c h o f i e l d & Vaarama 24131; R i c h a r d s o n I s l a n d , S c h o f i e l d & Vaarama 24222; L a g i n s Greek, Graham I s l a n d , 30021; B i g s b y I n l e t , Moresby I s l a n d , 32509; Van I n l e t , Graham I s l a n d , S c h o f i e l d & S j o r s 32148; Echo H a r b o u r , Moresby I s l a n d , 32496; Goose Cove, Graham I s l a n d , 30550; B l u e Heron Cove, Moresby I s l a n d 31384; Kootenay I n l e t , Moresby I s l a n d , 31146; P e e l I n l e t A r e a , Moresby I s l a n d , 30455 ; M a i n l a n d and a d j a c e n t I s l a n d s ; K e i t h Anchorage A r e a , C a l v e r t I s l a n d , S c h o f i e l d & W i l l i a m s 27115, 27109; N o r t h V a n couver, 19924; Long L a k e , C a l v e r t I s l a n d , S c h o f i e l d & W i l l i a m s 27837, 27902, 27907; Wigwam C r e e k , I n d i a n Arm, 20540; Horseshoe Bay, S c h o f i e l d & A n d e r s o n 33378; Deeks C r e e k , Howe Sound, 20666; Lake between B r i t t a n i a Beach and Squamish, 13119; W. o f Wedgeborough P t . , C a l v e r t I s l a n d , S c h o f i e l d & W i l l i a m s 2 7146; H a l f moon Bay, S'echelt P e n i n s u l a , S c h o f i e l d & Boas, 18060; M u r r i n Park n e a r Squamish, 20 34 7. I n t h e f o l l o w i n g specimens t h e gametophytes a r e c o m p a r a t i v e l y much s h o r t e r , 2 - 3.5 cm l o n g ( P I . I , f i g . 2 ) , d a r k e r and t h e c o s t a i s n o t r i d g e d i n t h e upper p o r t i o n ( P I . X V I I , f i g . 2 & 3 ) . Specimens examined: Queen C h a r l o t t e I s l a n d s : Sperm Bay, Moresby I s l a n d , 31732; K e i t h Anchorage A r e a , C a l v e r t I s l a n d , S c h o f i e l d & W i l l i a m s 27114, 26876; C e n t r e Bay, Gambier I s l a n d , D i l l 15562. 14 From s u b - a l p i n e a r e a s o f t h e Queen C h a r l o t t e I s l a n d s some sp e c i m e n s , o t h e r w i s e t y p i c a l , p o s s e s s l e a v e s w i t h b i s t r a t o s e m a r g i n s and w i t h o c c a s i o n a l p o r t i o n s o f t h e l a m i n a a l s o b i s t r a t o s e ( P I . I I , f i g . 7 ) . Specimens examined: P e e l I n l e t A r e a , Moresby I s l a n d 30438; C h a a t l I s l a n d , S c h o f i e l d & Boas 18760. T h i s i s t h e most d i s t i n c t i v e and l e a s t v a r i a b l e t a x o n o f t h e h e t e r o s t i c h u m complex i n B r i t i s h C o l u m b i a . The gametophytes a r e u n i f o r m l y w i t h o u t any s h o r t l a t e r a l b r a n c h l e t s , p o s s e s s l o n g , l a n c e o l a t e l e a v e s w i t h e l o n g a t e d upper c e l l s , r i d g e d c o s t a i n t h e upper p o r t i o n and w i t h t r a n s v e r s e l y r e c t a n g u l a r upper e x o t h e c i a l c e l l s . These c h a r a c t e r s a r e c o n s i s t e n t even i n d i f f e r e n t h a b i t a t s . The unbranched h a b i t and l o n g upper l e a f c e l l s r e a d i l y s e p a r a t e s t h i s t a x o n from o t h e r members o f t h e h e t e r o s t i c h u m complex and t h e d i s t i n c t l y r i d g e d c o s t a , e l o n g a t e d upper l e a f , c e l l s and l o n g h y a l i n e p o i n t from R. depressum L e s q . and R. a q u a t i c u m B r i d . As t h i s t a x o n i s c l e a r l y d i f f e r e n t from a l l o t h e r known s p e c i e s i t c o u l d be d e s c r i b e d as a s e p a r a t e s p e c i e s o f R h a c o m i t r i u m . Some specimens a r e d i s t i n c t l y b i s t r a t o s e i n t h e m a r g i n ; t h i s m ight be s e p a r a t e d as a v a r i e t y as i n t h e c a s e o f v a r . a f f i n e ( S c h l e i c h ) C„ J e n s , o f R. h e t e r o s t i c h u m w h i c h i s s e p a r a t e d m a i n l y on t h e b a s i s o f b i s t r a t o s e m a r g i n . S i n c e so few specimens a r e a v a i l a b l e and o n l y a s i n g l e d i s t i n g u i s h i n g 15 c h a r a c t e r i s i n v o l v e d , i t seems p r e s e n t l y most r e a s o n a b l e not to g i v e t h i s v a r i a t i o n any s p e c i a l taxonomic s t a t u s . I n s t e a d i t i s c o n s i d e r e d w i t h i n the v a r i a b i l i t y o f the taxon. The same h o l d s t r u e f o r the forms i n which the c o s t a i s not r i d g e d i n the upper p o r t i o n o f the l e a f . 16 R h a c o m i t r i u m h e t e r o s t i c h u m (Hedw. ) B r i d . Muse. Recent S:uppl. 4:79, 1819. Trichostomum h e t e r o s t i c h u m Hedw. Sp. Muse. 109, 1801. Dry p t o d o n c a r n o s u s B r i d . B r y o l . U n i v . 206, 1826. Trichostomum carnosum D i c k s ; B r i d . B r y o l . U n i v . 206, 1826. Trichostomum stenocarpum Hampe, i n Hueben Muse. Germ. 208, 1833. Grimmia h e t e r o s t i c h a C. M u e l l . Syn. 1:807, 1849. R h a c o m i t r i u m h e t e r o s t i c h u m Subsp. V u l q a r e L o e s k e , Laub. E u r . 1:183, 1913. Gametophytes g r e y i s h g r e e n t o dark brown, o f t e n b l a c k i s h ; stem 2 - 8 cm l o n g , e r e c t o r s p r e a d i n g u s u a l l y w i t h many s h o r t t u f t - l i k e l a t e r a l b r a n c h e s (about 1 - 3 mm l o n g ) and e l o n g a t e d b r a n c h e s (about 1 - 4 cm l o n g ) ( P I . I V , f i g . 1 & 2 ) ; r h i z o i d s l o n g , b r a n c h e d o r unbranched, few, t h i c k w a l l e d , smooth; l e a v e s l o o s e l y i m b r i c a t e d when d r y ( P I . I V , f i g . 1 & 2 ) , e r e c t s p r e a d i n g when m o i s t , l a n c e o l a t e , from a b r o a d b a s e , 2.2 - 3.1 mm l o n g i n c l u d i n g t h e 0.2 - 0.8 mm h y a l i n e p o i n t ( P I . X V I I I , f i g . 1-3) which i s e i t h e r t o o t h e d b o t h on t h e m a r g i n and s u r f a c e o r o n l y on t h e m a r g i n , n e v e r p a p i l l o s e ( P I . I V , f i g . 5 ) ; ma r g i n e n t i r e t o somewhat c r e n u l a t e a t apex and e n t i r e i n t h e l o w e r p o r t i o n , r e c u r v e d u s u a l l y on b o t h m a r g i n s b u t w i t h one s i d e more r e c u r v e d t h a n t h e o t h e r ( P I . X V I I I , f i g . 1-3), u n i s t r a t o s e t h r o u g h o u t ( P I . V, f i g . 1-4 and P I . V I , f i g . 5 ) ; upper l e a f c e l l s u s u a l l y i s o d i a m e t r i c a l ( P I . I V , f i g . 4 ) , sometimes a few s h o r t r e c t a n g u l a r , 5 - 8 AX i n d i a m e t e r , becoming g r a d u a l l y l o n g e r towards t h e m i d d l e o f t h e l e a f , median c e l l s r e c t a n g u l a r o r e l o n g a t e , about 13 - 2 3 /u l o n g and 5 /u b r o a d 17 ( P I . I V , f i g . 7 ) , l o w e r c e l l s e l o n g a t e d 15 - 38 AI l o n g and 3 - 5 AI b r o a d , s i n u o s e ( P I . I V , f i g . 6 ) ; a l a r c e l l s n o t d i s t i n c t , sometimes a few h y a l i n e c e l l s a t t h e b a s a l c o r n e r w i t h smooth w a l l s , b r o a d e r t h a n t h e r e s t , c e l l s a c r o s s base o f l e a f orange c o l o u r e d ; c o s t a p r o m i n e n t , f l a t t e n e d ( P I . I V , f i g . 3 ) , about 0.1 mm wide a t t h e b a s e , g r a d u a l l y n a r r o w i n g i n t h e upper p o r t i o n and e x t e n d i n g i n t o t h e h y a l i n e p o i n t , 2 - 4 s t r a t o s e , i n c r o s s - s e c t i o n t h e c e l l s o f t h e lo w e r row u s u a l l y b i g g e r t h a n t h e r e s t o r more o r l e s s e q u a l i n s i z e ; d i o e c i o u s ; o u t e r p e r i c h a e t i a l l e a v e s w i t h h y a l i n e p o i n t , c e l l s e l o n g a t e d , l o n g e r t h a n i n o r d i n a r y l e a v e s , upper c e l l s n o t s i n u o s e , i n n e r p e r i c h a e t i a l l e a v e s w i t h o u t h y a l i n e p o i n t , b r o a d and t h i n , c e l l s n o t s i n u o s e a t a l l ; p e r i g o n i a l l e a v e s b r o a d , much s h o r t e r , t h i n n e r , brown w i t h g r e e n t i p , u s u a l l y w i t h no h y a l i n e p o i n t , c e l l s n o t s i n u o s e . S p o r o p h y t e : s e t a s t r a i g h t , 4 - 7 mm l o n g , t w i s t e d t o t h e r i g h t , smooth; c a p s u l e e r e c t , c y l i n d r i c , 1.8 - 2.7 mm l o n g and 0.7 - 1.1 mm b r o a d ( P I . V, f i g . 6 ) , y e l l o w i s h brown, upper e x o t h e c i a l c e l l s r o u n d , q u a d r a t e o r mixed t y p e f o r 4 - 5 rows ( P I . V I , f i g . 1 ) , dark c o l o u r e d , m i d d l e c e l l s e l o n g a t e o r r e c t a n g u l a r ( P I . V I , f i g . 4 ) , l o w e r c e l l s mixed t y p e w i t h about 16 p h aneropore s t o m a t a ; p e r i s t o m e t e e t h 16, about 0.2 - 0.35 mm l o n g , f o r k e d i n t o 2 - 3 f i l i f o r m d i v i s i o n s , u s u a l l y o f d i f f e r e n t s i z e ( P I . V I , f i g . 1 ) , p a p i l l a e i r r e g u l a r l y p l a c e d , t r a n s v e r s e band p r o m i n e n t , s w o l l e n a t t h e m a r g i n , d i v i s i o n s j o i n e d a t v a r i o u s p l a c e s o r o n l y a t t h e base ( P I . V I , f i g . 3 ) ; c a l y p t r a m i t r a t e , p a p i l l o s e a t apex; operculum r o s t r a t e ( P I . V, f i g . 5 ) ; 18 a n n u l u s o f 2 - 3 rows o f r e d d i s h c e l l s , d e c i d u o u s ( P I . V I , f i g . 7 ) ; s p o r e s f i n e l y g r a n u l a r , 12 - 18 /u i n d i a m e t e r ( P I . V, f i g . 7 ) . S p o r o p h y t e m a t u r i n g i n summer o r l a t e s p r i n g . H a b i t a t : U s u a l l y on d r y c l i f f f a c e s and o u t c r o p s , o c c a s i o n a l l y i n damp shaded c l i f f w a l l s , u s u a l l y n e a r s e a l e v e l . G e n e r a l d i s t r i b u t i o n : • C i r c u m b o r e a l i n t h e N o r t h e r n Hemisphere: I n N o r t h A m e r i c a from A l a s k a t o G r e e n l a n d and L a b r a d o r , southward i n E a s t e r n A m e r i c a t o t h e s o u t h e r n A p p a l a c h i a n mountains o f N o r t h C a r o l i n a and Tennessee, s o u t h -ward i n Western A m e r i c a t o C a l i f o r n i a . I n E u r a s i a from I c e l a n d t o K a m t c h a t k a , southward i n J a p a n , K o r e a and Him a l a y a n a r e a ; a l s o ( a c c o r d i n g t o Van d e r W i j k e t a l , 1967) i n s o u t h e r n South A m e r i c a , N o r t h and South A f r i c a and A u s t r a l a s i a . Specimens examined: Queen C h a r l o t t e I s l a n d s : T u f t I s l a n d , E a s t o f L y e l l I s l a n d , S c h o f i e l d & Vaarama 24013, Vancouver I s l a n d : O t t e r p o i n t , 29453, M a i n l a n d and a d j a c e n t I s l a n d s : Gambier I s l a n d , C e n t r e Bay, 20755; Y a l e , F r a s e r R i v e r Bank,25586; P o i n t A t k i n s o n , N o r t h Vancouver, 13240; Mt. M a x w e l l , S T a l t s p r i n g I , Boas 436; G a b r i o l a I s l a n d , 22873; between Spuzzum and Y a l e , K r a j i n a s j . n . , Aug. 23, 1958. 19 V a r . a f f i n e ( S c h l e i c h ) C. J e n s , Danmarks Mossor 2:238, 192 3. Trichostomum a f f i n e S c h l e i c h , Gat (Ed 2) 31, 180 7. Trichostomum alopecurum S c h k u h r , D e u t s c h l Moose, 77, 1810. R h a c o m i t r i u m alopecurum B r i d . Mant. 79. 1819. R h a c o m i t r i u m f a s t i q i a t u m W a l l r . F l . K r y p t . 1:175, 1831. R h a c o m i t r i u m h e t e r o s t i c h u m v a r . alopecurum Hueben Muse. Germ. 208, 1833:. Trichostomum f a s c i c u l a r e , v a r . , T a y l . i n Mack. F l . H i b . 2:20, 1836. Trichostomum s a x a t i l e T a y l . T r a n s . B o t . S'oc. E d i b . 2 :1, 1845. Grimmia h e t e r o s t i c h a /3 a l o p e c u r a C. M u e l l , Syn 1:808, 1849. R h a c o m i t r i u m a f f i n e L i n d b . A c t a Soc. S c i . Fenn. 10:552, 1857. Grimmia a f f i n i s L i n d b . Muse. Scand. 29, 18 79. R h a c o m i t r i u m h e t e r o s t i c h u m , Subsp. m i c r o p o i d e s K i n d b . Hedwigia. 35:65, 1896. Grimmia s u b l u r i d a S t i r t , S c o t . N a t . 9:36, 1900. Grimmia. c a l v e s c e n s S t i r t , Ann. S c o t . Nat. H i s t . 10:112, 1901. Grimmia p a p i l l u l a t a S t i r t . Op. C i t . 11:110, 1902. R h a c o m i t r i u m h e t e r o s t i c h u m subsp. a f f i n e , Amann F l . Mouss. S u i s s e , 2:143, 1912. RTiacomitrium h e t e r o s t i c h u m v a r . L i m p r i c h t i i Loeske Laubm. ~ E u r . 1:184, 1913. Stem s l e n d e r , e l o n g a t e d o r s h o r t , 4 - 7 cm l o n g , w i t h numerous s l e n d e r f a s c i c u l a t e b r a n c h e s ( P I . V I I , f i g . 1 ) ; p l a n t s y e l l o w i s h g r e e n t o dark g r e e n ; l e a v e s o v a t e - l a n c e o l a t e , 1.8 - 3 mm l o n g w i t h h y a l i n e p o i n t s s h o r t e r ( P I . X V I I I , f i g . 4 ) , o f t e n a l m o s t o b s o l e t e , m a r g i n b i s t r a t o s e i n upper p a r t o f l e a f ( P I . V I I , f i g . 2, 4, 6 ) , u n i s t r a t o s e i n l o w e r p a r t ( P I . V I I , f i g . 3 ) ; c a p s u l e c y l i n d r i c a l , 2 - 2.9 mm l o n g and 0.6 - 1 ram 20 broad (PI. VI, f i g . 2). Sporophytes maturing i n la t e spring or summer. Habitat: On dry rocks. General d i s t r i b u t i o n : In Europe from the Eaeroe Islands, Scandinavia and S i b e r i a , southward to Spain and I t a l y ; i n North America from Newfoundland and Nova Scotia and from Alaska to B r i t i s h Columbia and Washington. Specimens examined: Queen Charlotte Islands: Moresby Island, 30805 A; Dass: Peninsula, Sc h o f i e l d & Vaarama 24482, Mainland and adjacent Islands: Point Atkinson, North Vancouver, 13242; Grafton Bay, Bowen Island, D i l l 20462; Saturn a Beach, Gulf of Georgia, 14399; M i l l Creek, McFadden s.n., Oct. 19, 1923. R. heterostichum sen, s t r . i s very v a r i a b l e i n s i z e , colour and mode of branching. In general, i t i s close to R". canescens B r i d . and R. fascicular.e (Hedw.) B r i d . i n habit but the very strong and d i s t i n c t p a p i l l o s e leaf c e l l s and hyaline point of R. canescens, and elongated upper c e l l s , mutic'ous leaf of R. f a s c i c u l a r e immediately separate these species. The character of branching pattern and unistratose margin suggests a strong r e l a t i o n s h i p between R. heterostichum and R. ramulosum Lindb., but the very short and pale capsule of R. ramulosum and elongated upper c e l l s are d i s t i n c t l y d i f f e r e n t from the long, c y l i n d r i c capsule and isodiametric 21 upper c e l l s o f R. h e t e r o s t i c h u m . I t i s a l s o c l o s e t o t h e R. b r e v i p e s K i n d b . group e s p e c i a l l y w i t h var. " m i c r o c a r p i f o r m i s " h a v i n g more o r l e s s s i m i l a r t y p e o f b r a n c h e s , u n i s t r a t o s e m a r g i n , l o n g c y l i n d r i c a l c a p s u l e b u t d i f f e r s i n t h e c h a r a c t e r o f upper c e l l s w h i c h a r e i s o d i a m e t r i c i n R. h e t e r o s t i c h u m b u t e l o n g a t e i n R. b r e v i p e s var. " m i c r o c a r p i f o r m i s " . V a r . a f f i n e i s v e r y d i f f i c u l t t o s e p a r a t e from R. h e t e r o s t i c h u m because a l l t h e c h a r a c t e r s a re t h e same e x c e p t f o r t h e b i s t r a t o s e n a t u r e o f t h e l e a f m a r g i n . 22 R h a c o m i t r i u m s u d e t i c u m (Funck) B. S. G. B r y o l . E u r , f a s c . 25-28, 1845. Trichostomum m i c r o c a r p o n Hedw. S.p. Muse. 112, 1801. Trichostomum s u d e t i c u m Funck, Moost. 26, 1821. D r y p t o d o n s u d e t i c u s B r i d . B r y o l . U n i v . 1:195, 1826. R h a c o m i t r i u m m i c r o c a r p o n fi s u d e t i c u m Hueben Muse. Germ. 302. 1833. Trichostomum q r a c i l e Hueben Op. C i t . 1. C. Grimmia p r o c e r a B a l s & Not. P u g i l l . no. 17, 1836. R h a c o m i t r i u m s u d e t i c u m B r . & Sch. B r y o l . E u r . f a s c . 25-28, 1845. Grimmia m i c r o c a r p a . C. M u e l l . Syn. 1:804, 1849. R h a c o m i t r i u m m i c r o c a r p o n L i n d b . A c t a . Soc. S c i . Fenn. 10:524, 1875. R h a c o m i t r i u m h e t e r o s t i c h u m , S'ubsp. s u d e t i c u m . D i x o n . S t u d . Handb. B r i t . Mosses (Ed. 1) 154, 1896. R h a c o m i t r i u m h e t e r o s t i c h u m v a r . s u d e t i c u m Jones Moss F l . N. Amer. I I : 57, 1933. Gametophytes y e l l o w t o dark g r e e n t o a l m o s t b l a c k , u s u a l l y s h o r t , l o o s e wide p a t c h e s ( P I . V I I I , f i g . 2 ) ; stem u s u a l l y 1 - 3 cm. ( r a r e l y up t o 8 cm) l o n g , b r a n c h e s a s c e n d i n g , u s u a l l y 0.5 - 3 cm ( r a r e l y 5 cm l o n g ) , s h o r t l a t e r a l b r a n c h e s few o r none ( i f p r e s e n t , about 1 - 3 mm l o n g ) ( P I . V I I I , f i g . 1)', r h i z o i d s a t t h e base o f t h e stem, b r a n c h e d o r unbranched, t h i c k w a l l e d , smooth; l e a v e s n o t t w i s t e d o r c u r l e d when d r y b u t e r e c t , u s u a l l y s p r e a d i n g o r l o o s e l y i m b r i c a t e d , l o n g l a n c e o l a t e f r om a b r o a d b a s e , about 2.5 - 3.3 mm l o n g i n c l u d i n g t h e 0.1 -0.3 mm h y a l i n e p o i n t ( P I . X I X , f i g . 1-4), h y a l i n e p o i n t d e n t i c u l a t e e i t h e r o n l y on t h e m a r g i n o r b o t h on t h e m a r g i n as w e l l as on t h e s u r f a c e (R. s u d e t i c u m var. o c c i d e n t a l e (Ren. & C a r d . ) F r y e , R. h e t e r o s t i c h u m var. s u d e t i c u m f . o c c i d e n t a l e 23 (Ren. & C a r d . ) J o n e s ) n o t p a p i l l o s e ( P I . V I I I , f i g . 6 ) ; upper c e l l s r ound t o s h o r t r e c t a n g u l a r , about 0.5 /u i n d i a m e t e r o r 10:5 AI ( P I . V I I I , f i g . 3 ) , median c e l l s u s u a l l y r e c t a n g u l a r , , sometime r o u n d , about 12:5 AX ( P I . V I I I , f i g . 4 ) ; l o w e r c e l l s e l o n g a t e , s i n u o s e 30 - 40 : 5 /u ( P I . V I I I , f i g . 5 ) ; a l a r c e l l s n o t d i s t i n c t , a few o f t h e lowermost c e l l s l i n e a r , not s i n u o s e , b r o a d e r t h a n t h e r e s t and y e l l o w brown i n c o l o u r , l e a f c e l l s a l m o s t smooth o r v e r y w e a k l y p a p i l l o s e i n t h e l o w e r p o r t i o n ; m a r g i n e n t i r e , r e v o l u t e o n l y on one s i d e ( P I . XIX, f i g . 1-4), l o w e r few m a r g i n a l c e l l s smooth w a l l e d and h y a l i n e ; b i s t r a t o s e f o r few rows a t l e a s t i n t h e upper h a l f o f t h e l e a f ( P I . I X , f i g . 1-3); c o s t a f l a t , e x t e n d i n g up t o o r i n t o t h e h y a l i n e p o i n t , about 80 /u w i d e , u s u a l l y b r o a d e r i n t h e m i d d l e , 2 - 4 s t r a t o s e ( P I . I X , f i g . 1-4); d i o e c i o u s ; p e r i c h a e t i a l l e a v e s t h i n , b r o a d e r t h a n r e s t o f t h e l e a v e s , c e l l s l i n e a r , e n t i r e e x c e p t a few i n upper p o r t i o n , w i t h h y a l i n e p o i n t , i n n e r l e a v e s l a r g e r t h a n t h e o u t e r ; p e r i g o n i a l l e a v e s much s h o r t e r , d a r k e r and t h i n n e r t h a n t h e r e s t o f t h e l e a v e s , u s u a l l y w i t h o u t h y a l i n e p o i n t , c o s t a t e . S p o r o p h y t e : s e t a s t r a i g h t , t w i s t e d t o t h e r i g h t , 3 - 3 . 5 mm l o n g , n o t p a p i l l o s e ; c a p s u l e e r e c t , e l l i p s o i d a l , u s u a l l y s m a l l , 0.6 - 2 mm l o n g and about 0.5 mm b r o a d , l i g h t t o dark brown, n o t p a p i l l o s e ( P I . I X , f i g . 5 ) ; upper 2 - 3 rows o f e x o t h e c i a l c e l l s round o r q u a d r a t e , r e d d i s h brown, l o w e r c e l l s o f mixed shape w i t h about 8 s t o m a t a , s l i g h t l y d a r k e r t h a n r e s t o f t h e c e l l s ; p e r i s t o m e t e e t h 16, about 0.3 mm l o n g , r e d d i s h brown a t t h e b a s e , y e l l o w - b r o w n i n t h e upper p o r t i o n , 24 p a p i l l o s e ( P I . I X , f i g . 9) and d i v i d e d i n t o 2 - 3 f i l i f o r m p r o n g s , u s u a l l y s t r a i g h t and o f same s i z e , u n i t e d a t t h e b a s e , t r a n s v e r s e - b a n d n o t p r o m i n e n t , m a r g i n t h i c k e n e d a t bands ( P I . I X , f i g . 6 ) ; a n n u l u s 1 - 2 rows o f g o l d e n y e l l o w c e l l s ( P I . I X , f i g . 7 ) ; o p e r c u l u m r o s t r a t e , u s u a l l y w i t h a s t r a i g h t beak, sometimes o b l i q u e , n o t p a p i l l o s e , about 1 mm l o n g ( P I . X, f i g . 8 ) ; c a l y p t r a n e a r l y smooth a t apex, l a c e r a t e and smooth a t b a s e ; s p o r e s r o u n d , g r a n u l a r , g r e e n i s h y e l l o w , about 12 -15 A i i n d i a m e t e r ( P I . I X , f i g . 8 ) . S p o r o p h y t e m a t u r i n g i n summer. H a b i t a t : On d r y exposed r o c k s and s o i l , u s u a l l y i n h i g h a l t i t u d e s and l a t i t u d e s , s u b - a l p i n e t o a l p i n e . G e n e r a l d i s t r i b u t i o n : A l a s k a and Yukon t o Oregon and I d a h o ; a c r o s s a r c t i c and b o r e a l Canada t o G r e e n l a n d , L a b r a d o r and Nova S c o t i a , southward t o New Hampshire and P e n n s y l v a n i a ; i n Europe from I c e l a n d t o F e n n o s c a n d i a , southward t o t h e A l p s , T a t r a s C a r p a t h i a n s and C a u casus, a l s o from A s i a M i n o r , and n o r t h e a s t e r n A s i a i n J a p a n . Specimens examined: Queen C h a r l o t t e I s l a n d s : Mt. de l a Touche, Moresby I s l a n d , F o s t e r & B i g g . s.n., June 28, 1961; Mt. Needham A r e a , Graham I s l a n d , F o s t e r & B i g g , s_.n. , June 18, 1961; T a k a k i a Lake, Moresby I s l a n d , 24891 $ 2.4965, 25025 , 25170; Moresby Mt. , Moresby I s l a n d , 32308; Head o f Dawson I n l e t , Graham I s l a n d , 15880; 25 Vancouver I s l a n d : Mt. M a x w e l l , M a c k e n z i e s.n., A u g u s t , 1930; V i c t o r i a , S a v a l e 57; Mt. A r r o w s m i t h , E l v i d g e K 1070. M a i n l a n d and a d j a c e n t I s l a n d s : Long L a k e , S c h o f i e l d & W i l l i a m s 2 7940; Whatshan L a k e , B e l l S'B 56; G a r i b a l d i P a r k , A r c h e r s.n. 12th A u g u s t , 1962; W e l l s Gray P r o v i n c i a l P a r k , Leena & A h t i 14230, 14193; Mt. B u x t o n , C a l v e r t I s l a n d , 28042; Mt.. Seymour, 12553; L i o n ' s Bay T r a i l , 19936; S m a l l Greek, Dam Mt., K r a j i n a s.n., Aug. 28, 1959; T o n q u i n V a l l e y , J a s p e r P a r k , McFadden s^n.:, J u l y , 1926; F i s h e r Maiden L a k e , S i l v e r t o n , Mc.Fadden s.n. June 27, 1926. 26 V a r . M a c o u n i i ( K i n d b . ) N. Comb. R h a c o m i t r i u m m a c o u n i i K i n d b . B u l l . T o r r . C l u b . 16:93, 1889. R h a c o m i t r i u m r o b u s t i f o l i u m K i n d b . Op. C i t . 17:272, 1890. R h a c o m i t r i u m a l t e r n u a t u m . C M . and K i n d b . i n Mac. C a t . Can. P I . 6:73, 1892. R h a c o m i t r i u m a t t e n u a t u m C M . and K i n d b . 1. C Grimmia r o b u s t i f o l i a K i n d b . E u r . and N. Am. B r y i n , 225, 1897. Grimmia a t t e n u a t a K i n d b . 1. C. 228. R h a c o m i t r i u m h e t e r o s t i c h u m v a r . m a c o u n i i Jones Moss. F l . N. Amer. 11:57, 1933. Gametophytes g r e e n o r b r o w n i s h , y e l l o w i s h g r e e n on t h e t o p o f a s c e n d i n g b r a n c h e s , s h o r t l a t e r a l b r a n c h l e t s a b s e n t , stem 3 - 8 cm l o n g ; l e a v e s l a n c e o l a t e , somewhat t w i s t e d o r c u r l e d when d r y ( P I . X, f i g . 2 ) , l o o s e , w i t h o r w i t h o u t h y a l i n e p o i n t , i f p r e s e n t , s h o r t , u s u a l l y b l u n t ( P I . X, f i g . 3 & 6 ) , upper l e a f c e l l s u s u a l l y round o r s h o r t r e c t a n g u l a r , g r a d u a l l y l o n g e r and n a r r o w e r downward ( P I . X, f i g . 5 & 7 ) ; mar g i n r e v o l u t e o n l y on one s i d e ( P I . XX, f i g . 1-3), b i s t r a t o s e f o r few rows i n more t h a n h a l f t h e whole l e a f . S p o r o p h y t e : s e t a about 3 - 5 mm; c a p s u l e e l l i p s o i d a l o r c y l i n d r i c a l , 1 - 1.8 mm l o n g and 0.3 - 0.6 mm broad ( P I . X, f i g . 4 ) . S p o r o p h y t e m a t u r i n g i n summer. H a b i t a t : On a l p i n e and s u b - a l p i n e r o c k s and s o i l . G e n e r a l d i s t r i b u t i o n : P r o b a b l y endemic t o Western N o r t h A m e r i c a : A l a s k a southward t o B r i t i s h C o l u m b i a , A l b e r t a , Montana and W a s h i n g t o n . 27 Specimens examined: Queen C h a r l o t t e I s l a n d s : M o s q u i t o L a k e , Moresby I s l a n d , 2 5 4 3 3 o Vancouver I s l a n d : A r r o w s m i t h T r a i l , Boas 1530, 1532, 1505; A l b e r t Edward Mt., F o r b i d d e n P l a t e a u , Boas 1598; L i l l o o e t Macoun s_.n„ J u l y , 1916. M a i n l a n d and a d j a c e n t I s l a n d s : G a r i b a l d i P a r k , P e t e r s o n BP 52; A r c h e r s.n., 6 t h A u g u s t , 1962, 23r d September, 1962; N o r t h E a s t G a r i b a l d i , A r c h e r s_.n. , 22nd September, 1961; Grouse M o u n t a i n , P e t e r s o n BP 96, BP 100; Mt. Seymour 12432, 15985, 15947, 16013, 16000; S e n t i n e l G l a c i e r A r e a , G a r i b a l d i L a k e , S c h o f i e l d & Worley 32936; W e l l s Gray P r o v i n c i a l P a r k , Leena & A h t i 13953; Lion.'s Bay T r a i l , 19906. R. s u d e t i c u m i s f a i r l y c o n s i s t e n t i n most o f i t s c h a r a c t e r s . The s l e n d e r h a b i t , absence o f any s h o r t l a t e r a l b r a n c h e s , b i s t r a t o s e margin and s h o r t o v o i d c a p s u l e a re d i s t i n c t i v e . T h i s t a x o n i s r e l a t e d t o R. h e t e r o s t i c h u m i n i t s p o s s e s s i o n o f upper l e a f c e l l s p r e d o m i n a n t l y i s o d i a m e t r i c b u t t h e h a b i t , b r a n c h i n g p a t t e r n , margin o f t h e l e a f and a l s o c a p s u l e shape and s i z e a r e much d i f f e r e n t from R. h e t e r o s t i c h u m . Though some t a x o n o m i s t s have r e c o g n i z e d R. s u d e t i c u m as a sub-s p e c i e s o r v a r i e t y o f R. h e t e r o s t i c h u m ( D i x o n 1896, Jones 1933, Nyholm 1956), I f e e l t h a t R. s u d e t i c u m i s s u f f i c i e n t l y d i s t i n c t f r o m R. h e t e r o s t i c h u m t o m e r i t s p e c i f i c r a n k . T h i s i s a l s o t h e 28 g e n e r a l o p i n i o n o f s e v e r a l c u r r e n t European b r y o l o g i s t s ( M a r t e n s s o n , 1956, A u g i e r , 1966). V a r . m a c o u n i i , i n h a b i t , b r a n c h i n g p a t t e r n , l e a f m a r g i n , e t c . i s c l o s e r t o R. s u d e t i c u m t h a n t o R„ h e t e r o s t i c h u m . E x c e p t f o r t h e h y a l i n e p o i n t w h i c h i s s h o r t o r even a b s e n t and l e a v e s somewhat c u r l e d o r t w i s t e d when d r y i t i s s i m i l a r t o R.. s u d e t i c u m . Indeed i t i s p o s s i b l e t h a t R. m a c o u n i i may u l t i m a t e l y p r o v e t o be i d e n t i c a l t o R. s u d e t i c u m . 29 R h a c o m i t r i u m b r e v i p e s K i n d b . B u l l . T o r r . C l u b . 17:272, 1890 (Nov) R h a c o m i t r i u m h e t e r o s t i c h u m v a r . o c c i d e n t a l e Ren & C a r d . B o t . Gaz. 15:41, 1890 (Feb.) R h a c o m i t r i u m m i c r o p u s K i n d b . i n Mac. C a t . Can. P I . 6:97, 1892. R h a c o m i t r i u m o c c i d e n t a l e Ren. & C a r d . Muse. Am. S e p t . 25, 189 3. R h a c o m i t r i u m h e t e r o s t i c h u m subsp. s u d e t i c u m v a r . o c c i d e n t a l e (Ren. & Card.) F r y e B r y o l o g i s t 21:3, 1918 R h a c o m i t r i u m h e t e r o s t i c h u m v a r . s u d e t i c u m f . o c c i d e n t a l e TRen. & Card.) Jones Moss. F l . N. Amer. 11:57, 1933. Gametophyte dark b r o w n i s h o r y e l l o w i s h g r e e n ; stem 3 - 6 cm l o n g w i t h few t o numerous s h o r t l a t e r a l b r a n c h l e t s (about 1 - 4 mm l o n g ) and a l s o a s c e n d i n g b r a n c h e s (about 1 - 4 cm l o n g ) ( P I . X I , f i g . 1 & 2 ) ; r h i z o i d s b r a n c h e d , smooth, t h i c k w a l l e d ; l e a v e s l o o s e l y i m b r i c a t e d when d r y , s p r e a d i n g when wet, o v a t e - l a n c e o l a t e , 2.5 - 5.6 mm i n c l u d i n g 0.5 - 1.4 mm h y a l i n e p o i n t ( P I . X X I , f i g . 1 & 2 ) ; h y a l i n e p o i n t s t r o n g l y t o o t h e d b o t h on t h e m a r g i n and on t h e s u r f a c e , n o t p a p i l l o s e ( P I . X I , f i g . 3 ) , upper c e l l s e l o n g a t e d , sometimes mixed w i t h r e c t a n g u l a r o r q u a d r a t e c e l l s , u s u a l l y 8 - 2 3 Ai : 5 /u, s i n u o s e , n o t o r s l i g h t l y p a p i l l o s e ( P I . X I , f i g . 5 ) , median c e l l s e l o n g a t e , s i n u o s e , 8 - 3 8 / u : 3 - 5 / u ( P I . X I , f i g . 6 ) , l o w e r c e l l s l o n g , s i n u o s e 18 - 64 /u : 4 - 5 /u, s l i g h t l y p a p i l l o s e o r n o t ( P I . X I , f i g . 4 ) ; margin e n t i r e t o somewhat c r e n u l a t e a t t h e apex, e n t i r e i n t h e l o w e r p o r t i o n , b i s t r a t o s e , m o s t l y n o t i n t h e upper p o r t i o n b u t i n t h e m i d d l e p o r t i o n , sometimes l a m i n a a l s o b i s t r a t o s e ( P I . X I I , f i g . 3, 5 & 6 ) , l a m i n a l c e l l w a l l s appear p a p i l l o s e i n c r o s s s e c t i o n l a r g e l y due t o t h e 30 g r e a t l y t h i c k e n e d c r o s s w a l l s , n e v e r p a p i l l o s e o v e r t h e lumen ( P I . X I I , f i g . 3-6), margin r e v o l u t e e i t h e r on one o r b o t h s i d e s ( P I . X X I , f i g . 1 & 2 ) , sometimes up t o t h e apex; c o s t a f l a t , e x t e n d i n g i n t o t h e h y a l i n e p o i n t , b r o a d e r i n t h e m i d d l e , about 0.1 mm w i d e , g r a d u a l l y becoming l e s s wide i n t h e upper p o r t i o n , 2 - 4 s t r a t o s e ( P I . X I I , f i g . 2, 3, 5 & 6 ) ; d i o e c i o u s ; i n n e r p e r i c h a e t i a l l e a v e s b r o a d e r and t h i n n e r , c e l l s l o n g e r , w i d e r , u s u a l l y n o t s i n u o s e and w i t h o u t h y a l i n e p o i n t ; p e r i g o n i a l l e a v e s s h o r t e r , b r o a d e r and d a r k e r (brown) t h a n r e s t o f t h e l e a v e s , c e l l s u s u a l l y n o t s i n u o s e e x c e p t a t t h e t i p . S p o r o p h y t e : s e t a s t r a i g h t , t w i s t e d t o t h e r i g h t n o t p a p i l l o s e , u s u a l l y 4 - 7 mm l o n g , sometimes l o n g e r ; c a p s u l e e r e c t , c y l i n d r i c 2 - 3 mm l o n g and 0.6 - 0.9 mm b r o a d , l i g h t t o d a r k brown i n c o l o u r , n o t p a p i l l o s e ( P I . X I I , f i g . 1 ) ; upper 2 - 4 rows o f e x o t h e c i a l c e l l s more o r l e s s round ( P I . X I I I , f i g . 3 ) , r e d d i s h brown, l o w e r c e l l s round o r r e c t a n g u l a r w i t h 14 - 32 s t o m a t a , stomata p r o m i n e n t , c e l l s d a r k e r t h a n r e s t o f t h e c e l l s ( P I . X I I I , f i g . 2 ) ; p e r i s t o m e t e e t h 16, about 0.3 mm l o n g , f o r k e d , b r a n c h e s u n i t e d o r f r e e , o f same o r o f d i f f e r e n t l e n g t h , p a p i l l o s e , t r a n s v e r s e band n o t o r s w o l l e n a t t h e m a r g i n , n o t p r o m i n e n t ( P I . X I I I , f i g . 1 ) ; a n n u l u s 1 o r 2 rows o f y e l l o w c e l l s , d e c i d u o u s ( P I . X I I I , f i g . 4 ) ; op e r c u l u m r o s t r a t e , about 1 mm l o n g , n o t p a p i l l o s e ( P I . X I I I , f i g . 5 ) ; c a l y p t r a c o n i c a l , about 2 mm l o n g , d i v i d e d i n t o 7 l a c e r a t i o n s w h i c h a r e f u r t h e r d i v i d e d i n t o 2 - 3 p a r t s , somewhat rough i n t h e apex ( P i . X I I I , f i g . 6 ) ; s p o r e s r o u n d , g r a n u l a r , g r e e n i s h brown i n c o l o u r 12 - 15 A I i n d i a m e t e r . 31 S p o r o p h y t e s m a t u r i n g i n s p r i n g . H a b i t a t : On d r y r o c k s , s u b - a l p i n e . G e n e r a l d i s t r i b u t i o n : Endemic t o Western N o r t h A m e r i c a : A l a s k a southward t o Washington. Type l o c a l i t y on s l o p i n g g a r n e t i f e r o u s r o c k s n e a r t h e summit o f t h e G o l d r a n g e , N o r t h o f G r i f f i n L a k e , B r i t i s h G o l u m b i a , a l t i t u d e 6,700 f e e t . Specimens examined: Vancouver I s l a n d : Teanook Lake , 1362 7, M a i n l a n d and a d j a c e n t I s l a n d s : Decanso Bay, G a b r i o l a I s l a n d , 13627; L i o n ' s Bay T r a i l , 19907; K e i t h Anchorage A r e a , C a l v e r t I s l a n d , S c h o f i e l d & W i l l i a m s 26900; Mts. N. o f G r i f f i n L a k e , Macoun, s.n., Aug. 9 t h , 1889, CAN; S e l k i r k and G o l d Range M o u n t a i n s , Macoun 614, CAN. 32 V a r . " l a e v i s " • v a r . nov. Gametophytes i n l o o s e b r o w n i s h g r e e n , o f t e n b r i g h t g r e e n t u f t s ; stems 2.5 - 8 cm l o n g w i t h few t o numerous s h o r t l a t e r a l b r a n c h l e t s (about 1 - 4 mm l o n g ) and a l s o a s c e n d i n g b r a n c h e s (about 1 - 4 cm l o n g ) ( P I . XIV, f i g . 1 ) ; l e a v e s l a n c e o l a t e from a b r o a d base ( P I . X X I , f i g . 3 & 4 ) ; upper c e l l s r e c t a n g u l a r o r e l o n g a t e d , m a r g i n b i s t r a t o s e ( P I . XIV, f i g . 3 & 6 ) , l a m i n a l c e l l w a l l s n o t p a p i l l o s e i n c r o s s s e c t i o n , l i t t l e t h i c k e n i n g on c r o s s w a l l ( P I . XIV, f i g . 2 - 6 ) , h y a l i n e p o i n t e i t h e r t o o t h e d o n l y on t h e m a r g i n o r b o t h on t h e m a r g i n and s u r f a c e b u t d e n t i c u l a t i o n s n e v e r as s t r o n g as i n R. b r e v i p e s s e n . s t r . S p o r o p h y t e s : s e t a s t r a i g h t , 4 - 8 mm l o n g , c a p s u l e c y l i n d r i c , 2 - 3.7 mm l o n g and 0 . 7 - 1 mm b r o a d . S p o r o p h y t e m a t u r i n g i n s p r i n g t o summer. H a b i t a t ; On d r y exposed r o c k s . Specimens examined: Queen C h a r l o t t e I s l a n d s : Graham I s l a n d , 29 768; Dass P o i n t P e n i n s u l a , S c h o f i e l d & Vaarama 24430; T u f t I s l a n d , S c h o f i e l d & Vaarama 24018; Lagoon I n l e t , 31983, Vancouver I s l a n d : Mt. T o l m i e , Boas 1174; O t t e r P o i n t , 29444; Mt. B r u c e , S a l t s p r i n g I , Boas 313; Golden H i n d a A r e a , D o l l e r y - P ardy s.n. , June 8, 1963; Long Beach, 26544. M a i n l a n d and a d j a c e n t I s l a n d s : Horseshoe Bay, K r a j i n a 302 3; Shames, Skeena R i v e r , S c h o f i e l d & Boas 21442; Long L a k e , 33 Mt. B u x t o n , S c h o f i e l d & W i l l i a m s 27914; P a u l R i d g e , G a r i b a l d i P a r k , 14469; Deek's Greek, Howe Sound, 35757; A r m s t r o n g , W i l s o n s_.n. , O c t o b e r 26, 1963; J u n c t i o n o f L i l l o e t and F r a s e r R i v e r , 36145; Lund, M a l a s p i n a P e n i n s u l a , S c h o f i e l d & Boas 18182; P o i n t A t k i n s o n , N o r t h Vancouver, 13242. 34 V a r . "eramulosum" v a r . nov. Gametophytes w i t h l i g h t g r e e n t o b r o w n i s h green stems, 2 - 8 cm l o n g w i t h u s u a l l y no s h o r t l a t e r a l b r a n c h e s o r few, e l o n g a t e d b r a n c h e s about 1 - 3.5 cm l o n g ( P I . Xv, f i g . 1) ; l e a v e s l a n c e o l a t e from a b r o a d base ( P I . X X I I , f i g . 1) ; upper c e l l s e l o n g a t e d o r r e c t a n g u l a r , sometimes mixed w i t h round c e l l s , m a r g i n b i s t r a t o s e , l a m i n a l c e l l w a l l s n o t p a p i l l o s e i n c r o s s s e c t i o n ; h y a l i n e p o i n t s h o r t t o l o n g , t o o t h e d o n l y on the margin o r b o t h on t h e m a r g i n and s u r f a c e . S p o r o p h y t e : s e t a s t r a i g h t , 3 - 6 mm, sometimes up t o 9.5 mm l o n g ; c a p s u l e e r e c t , c y l i n d r i c 1.7 - 2.7 mm l o n g and 0.3 - 0.9 mm b r o a d ( P I . XV, f i g . 2 ) . S p o r o p h y t e m a t u r i n g i n l a t e s p r i n g t o summer. H a b i t a t : On r o c k s ; s u b - a l p i n e . G e n e r a l d i s t r i b u t i o n : P r o b a b l y endemic t o N o r t h w e s t e r n N o r t h A m e r i c a , west o f t h e Rocky M o u n t a i n s . Specimens examined: Queen C h a r l o t t e I s l a n d s : T a k a k i a L a k e , 25144; Skedans, 31896. Vancouver I s l a n d : A r r o w s m i t h T r a i l , Boas 1457; Mt. B r u c e , S a l t s p r i n g I , Boas 301. M a i n l a n d and a d j a c e n t I s l a n d s : U.B.C. F o r e s t , Haney, K r a j i n a 37; West pass L a k e , C a r i b o o d i s t r i c t , Boas 428; Howard L a k e , Hazlewood 4; C a l v e r t I s l a n d , 28000; Pochahantas L o o k o u t , 35 S t r a i g h t of Georgia, Schofield & Boas. 18255; Mt, Seymour, Peterson BP 27; Isaac Lake, Boas 606; Ga r i b a l d i Lake T r a i l , 28098; Halcyon, McFadden 39 3. 36 Var. "microcarpiformis". var. nov. Gametophytes l i g h t green to dark green, r a r e l y brown to almost black; stem 2 - 6 cm long with few to numerous short l a t e r a l branchlets (about 1 - 4 mm long) and also ascending branches (about 1 - 4 cm long) (PI. XV, f i g . 4); leaves 2 - 5 mm long, lanceolate with 0.5 - 2.5 mm hyaline point (PI. XXII, f i g . which i s denticulate e i t h e r on the margin only or both on the margin and surface; upper c e l l s elongated or rectangular (PI. XV, f i g . 3) gradually longer and narrower downward (PI. XV, f i g 5 & 6) margin revolute on one side or both (PI. XXII, f i g . 2 unistratose throughout (PI. XVI, f i g . 1-4), laminal c e l l s not p a p i l l o s e i n cross section; costa extending i n t o or up to hyaline point, 2 - 4 stratose. Sporophyte: Seta 4.5 - 7.5 mm long; capsule erect, 1.5 - 3.6 mm long and 0.5 - 0.9 mm broad (PI. XIII, f i g . 7); operculum r o s t r a t e or c o n i c a l ; peristome teeth always forked, usually a l l of equal length, e i t h e r free or joined at various places; spores round, granular, 10 - 15 /u i n diameter (PI. XVI, f i g . 6). Sporophytes maturing throughout the year. Habitat: On dry, exposed rocks or damp, shaded c l i f f s or boulders i n f o r e s t . Specimens examined: Queen Charlotte Islands: Louise Island, Schofield & Vaarama 23911-A; Rose Harbour, 31869; Tow H i l l , 29859; Moresby Island, 30737, 30746 A, 25296; Hotspring, 31888; Skedans, 31910; 37 Moresby Camp, 305 31; Gumshewa Head, 32 368. Vancouver: Island: Colwood, 16404; Mt. Bruce, Boas 290; Elk F a l l s , 16198; Beaver Lake, Macoun s.n., 17. 3. 1914; Sidney, Macoun s.n., 13. 12. 1912, 31. 3. 1916, 16. 4. 1916; Saanich Pen, Schofield & Chuang 35845; 2nd Bridge, Nanaimo River Valley, Mueller - Dombois, 104-7; Kangaroo Road, 35938; Langford, Schofield & Chuang 35864; Halibut Island, 20445; Humpback Road, 35976; Thetis Lake, Boas 1352; Beaver Lake, Macoun s.n., 17. 3. 1914; Mt. Douglas, Boas 953; M i l l H i l l , 29486; Amphitrite Point, Schofield & Boas 19016; Tofino, along Taylor River, 13486. Mainland and adjacent Islands: Benett Bay, Schofield & Boas 17497; Point Atkinson, N. Vancouver, 13258, 13256; Ashlu V a l l e y , Wlddowson s_.n. , Sept. 1963; Revelstoke, 27775 ; Burns Bog, Schofield & Taylor 35 767; Gambier Island, Howe Sound, Sch o f i e l d 20724; B r i t t a n i a Beach, Howe Sound, 12603; Cypress Creek, 14348; Hall's Gate, Fraser River Gorge, Schofield & Boas 17689; Highway # 1, Revelstoke, Anastasiou s.n., May 7, 1963; Lois River, Long Bay, Scho f i e l d & Boas 18374; Big Oliver Creek, Skeena River, Schofield & Boas 21171; Kaslo, Kootenay d i s t r i c t , B e l l , s.n., Aug. 21, 1959; Acadia Camp, U.B.C., 11435 ; Wilson Lake, B e l l . s_.n„ , June 17, 1959; Haney, University Forest, Schofield & O r l o c i 16312; Indian Arm, 20559; Hope, Sch o f i e l d & Williams 23428; Junction of L i l l o e t and Fraser River, 36140; Head of Knight I n l e t , Widdowson, s_.n. , July 7, 1962; Dam of Cheakamus River, Schofield & Lang 26156; Lynn Creek Canyon, W. Vancouver, 13343; Burton, B e l l s.n., June 27, 38 1959; K e i t h Anchorage A r e a , C a l v e r t I s l a n d , S c h o f i e l d & W i l l i a m s 27006; Wigwam Cre e k , I n d i a n Arm, 20527; Y a l e , S c h o f i e l d & Boas 17788; M u r r i n P a r k , 14507; New Denver, Eadden s.n., June 9, 1923; T r o u t L a k e , S e c h e l t P e n i n s u l a , S c h o f i e l d & Boas 18038; M c D o n e l l L a k e , Boas 564; M a r t h a C r e e k , K r a j i n a s.n., J u l y 23, 1954. I n B r i t i s h C o l u m b i a t h e commonest r e p r e s e n t a t i v e s o f t h e R. h e t e r o s t i c h u m complex (R. b r e v i p e s s e n s . l a t . ) a r e p l a n t s c h a r a c t e r i z e d by r e l a t i v e l y e l o n g a t e d upper c e l l s , few t o numerous s h o r t l a t e r a l b r a n c h l e t s , f a i r l y l o n g h y a l i n e p o i n t , and smooth o r s e e m i n g l y p a p i l l o s e l e a f c e l l s . I n t h e s e c h a r a c t e r s R. b r e v i p e s r e s e m b l e s R. m i c r o c a r p o n B r i d . , a s p e c i e s endemic t o Europe. But many p l a n t s o f R. b r e v i p e s i n B r i t i s h C o l u m b i a a r e d i s t i n c t l y b i s t r a t o s e i n t h e l e a f m a r g i n and t h e c a p s u l e s a re moderate t o l o n g w h i c h i s n o t t h e c a s e i n R. m i c r o c a r p o n . Nor do t h e y l o o k l i k e European specimens. R° b r e v i p e s s e n s . l a t . d i f f e r s from R. h e t e r o s t i c h u m B r i d . i n i t s p o s s e s s i o n o f upper e l o n g a t e d o r r e c t a n g u l a r c e l l s and, e x c e p t f o r v a r . " m i c r o c a r p i f o r m i s " , have b i s t r a t o s e l e a f m a r g i n s and match t h e t y p e o f R. b r e v i p e s K i n d b . I n t h e t y p e d e s c r i p t i o n t h e c a p s u l e o f R. b r e v i p e s i s d e s c r i b e d as s h o r t b u t i n t h e t y p e specimen a t t h e N a t i o n a l Museum o f Canada no c a p s u l e s a r e p r e s e n t . R. b r e v i p e s K i n d b . i s sometimes t r e a t e d as a synonym o f R. h e t e r o s t i c h u m v a r . o c c i d e n t a l e Ren. & C a r d , o r R. h e t e r o s t i c h u m v a r . s u d e t i c u m f . o c c i d e n t a l e (Ren. & Card) J o n e s , b u t t h e d e s c r i p t i o n and t y p e specimen o f R. b r e v i p e s 39 show t h a t i t has few t o numerous s h o r t l a t e r a l b r a n c h e s , r e c t a n g u l a r t o e l o n g a t e upper l e a f c e l l s and t h u s c a n n o t be c o n s i d e r e d i d e n t i c a l t o R. s u d e t i c u m . Moreover, t h e c h a r a c t e r o f t h e d e n t i c u l a t e h y a l i n e p o i n t b o t h on t h e m a r g i n and on t h e s u r f a c e , used t o s e p a r a t e R. o c c i d e n t a l e Ren. & C a r d , from R. s u d e t i c u m i s u n r e l i a b l e s i n c e i n a l l o t h e r members o f t h i s complex I have s e e n , t h i s c h a r a c t e r i s not c o r r e l a t e d w i t h any o t h e r . Thus i t c a n n o t be t a k e n as a c h a r a c t e r by w h i c h we can s e p a r a t e a v a r i e t y o r even a form. I n consequence h e r e I have s e p a r a t e d R. b r e v i p e s as b e i n g q u i t e d i s t i n c t from R. s u d e t i c u m o r R. o c c i d e n t a l e no m a t t e r what c a t e g o r y t h e s e t a x a are a c c o r d e d . V a r . " l a e v i s " and v a r . "eramulosum" have been s e p a r a t e d f rom R. b r e v i p e s s e n s . l a t . based on t h e f a c t t h a t t h e i r l e a f c e l l s a r e n o t p a p i l l o s e i n c r o s s s e c t i o n which I c o n s i d e r q u i t e an i m p o r t a n t c h a r a c t e r s i n c e t h e a n a t o m i c a l c h a r a c t e r s appear t o be l e s s a f f e c t e d by e n v i r o n m e n t a l changes t h a n t h e g r o s s morphology. Based on t h e c h a r a c t e r o f b r a n c h i n g p a t t e r n v a r . " l a e v i s " and v a r . "eramulosum" have been s e p a r a t e d from each o t h e r . V a r . " m i c r o c a r p i f o r m i s " forms a d i s t i n c t v a r i e t y c h a r a c t e r i z e d by t h e p r e s e n c e o f r e c t a n g u l a r o r e l o n g a t e d upper c e l l s , few t o numerous s h o r t l a t e r a l b r a n c h l e t s b u t u n i s t r a t o s e l e a f m a r g i n . T h i s v a r i e t y c o u l d be p l a c e d i n K. m i c r o c a r p o n e x c e p t f o r t h e v e r y d i f f e r e n t c a p s u l e s and t h e h a b i t . As t o t h e c h a r a c t e r o f b r a n c h i n g p a t t e r n , upper c e l l s and h y a l i n e p o i n t t h e y a r e l i k e R. b r e v i p e s and a r e , t h e r e f o r e , p l a c e d as v a r i e t y o f t h a t s p e c i e s . ko Key t o t h e R h a c o m i t r i u m h e t e r o s t i c h u m complex i n B r i t i s h C o l u m b i a A. Upper c e l l s q u a d r a t e o r round (1:1) o c c a s i o n a l l y mixed w i t h r e c t a n g u l a r c e l l s (2-3:1) ... B A-. Upper c e l l s p r e d o m i n a n t l y e l o n g a t e (4-20:1) sometimes mixed w i t h r e c t a n g u l a r c e l l s (2-3:1) ... E B. M a r g i n u n i s t r a t o s e i n upper p a r t o f l e a f ... R„ h e t e r o s t i c h u m s e n , s t r . B. M a r g i n b i s t r a t o s e ( r a r e l y w i t h u n i s t r a t o s e p o r t i o n s ) i n u p p e r p a r t o f l e a f ... C C„ B i s t r a t o s e p o r t i o n s c o n f i n e d t o one t o two rows o f m a r g i n a l c e l l s ; s h o r t l a t e r a l b r a n c h e s u s u a l l y more t h a n 10 ... R. h e t e r o s t i c h u m v a r . a f f i n e C. B i s t r a t o s e p o r t i o n e x t e n d i n g w e l l i n t o l a m i n a ; s h o r t l a t e r a l b r a n c h e s u s u a l l y fewer t h a n 3 ... D D. H y a l i n e p o i n t u s u a l l y 0.1 - 0.3 mm l o n g ( a t l e a s t on upper p a r t o f t h e s t e m ) , and w i t h up t o 14 t e e t h on one s i d e ... R„ s u d e t i c u m D„ H y a l i n e p o i n t a b s ent t o v e r y s h o r t ( l e s s t h a n 50 /u) , and w i t h l e s s t h a n 4 t e e t h on one s i d e i f h y a l i n e p o i n t i s p r e s e n t ... R. s u d e t i c u m v a r . macounii E. L e a f i n c r o s s : s e c t i o n w i t h c r o s s -w a l l s c o n s p i c u o u s l y r i d g e d , r e s e m b l i n g p a p i l l a e ; h y a l i n e p o i n t s t r o n g l y t o o t h e d b o t h on m a r g i n and s u r f a c e ... R. b r e v i p e s s e n , s t r , E„ L e a f i n c r o s s s e c t i o n w i t h c r o s s -w a l l s smooth, n e v e r a p p e a r i n g p a p i l l o s e ; h y a l i n e p o i n t u s u a l l y t o o t h e d o n l y on margin o r sometimes weakl y t o o t h e d on s u r f a c e as w e l l ... F hi CONT. Upper l e a f c e l l s m a i n l y e l o n g a t e (9-15:1) l e a f s t r o n g l y k e e l e d i n upper p a r t , t h u s t h e upper s u r f a c e s t r o n g l y V-shaped i n c r o s s s e c t i o n R. "laxum" Upper l e a f c e l l s mainly" r e c t a n g u l a r (2-3:1) o r e l o n g a t e (5:1) o r some-t i m e s mixed w i t h 1 : 1 . c e l l s ; l e a f n o t s t r o n g l y k e e l e d i n upper p a r t , t h u s t h e upper s u r f a c e b r o a d l y U-shaped i n c r o s s s e c t i o n M a r g i n u n i s t r a t o s e t h r o u g h o u t R. b r e v i p e s v a r . " m i c r o c a r p i f o r m i s " G. M a r g i n w i t h o c c a s i o n a l b i s t r a t o s e p o r t i o n s H H „ S h o r t l a t e r a l b r a n c h e s f e w e r t h a n 3 o r a b s e n t o R. b r e v i p e s v a r , "eramulosum" Ho S h o r t l a t e r a l b r a n c h e s u s u a l l y 4-15 Ro b r e v i p e s v a r , " l a e v i s " TABLE I Comparison between d i f f e r e n t s p e c i e s o f t h e R.„ h e t e r o s t i c h u m complex i n B r i t i s h C o l u m b i a C h a r a c t e r s "laxum" h f t e r o s s u d e t i c u m b r e v i p e s ticnum — P l a n t s u s u a l l y v e r y l o n g (L) s h o r t L 1' 1 1» (1) o r medium ( 1 ' ) ; s i z e o f . s t e m 5-16 cm 2-8 cm 1-3 cm 3-6 cm S h o r t l a t e r a l b r anches u s u a l l y „. p r e s e n t ( S ) , absent (s) s b s S H y a l i n e p o i n t always p r o m i n e n t and l o n g ( H); v e r y s h o r t (h) H h-H h-H H H y a l i n e p o i n t u s u a l l y t o o t h e d b o t h on t h e margin as w e l l a-s s u r f a c e t t-T t-T t-T (T) o n l y on t h e margin ( t ) Upper l e a f c e l l s p r e d o m i n a n t l y e l o n g a t e ( E ) , round ( e ) , E e e e'-E r e c t a n g u l a r (e') M a r g i n o f l e a f r e v o l u t e on b o t h ^ ^ ' s i d e s ( R ) , o n l y one s i d e ( r ) M a r g i n u n i s t r a t o s e t h r o u g h o u t (U) b i s t r a t o s e (u) When b i s t r a t o s e , u s u a l l y f o r many rows (B), f o r o n l y one row (b) C o s t a f l a t ( F ) , r i d g e d i n t h e upper p o r t i o n ( f ) u-U u-U u u-U B b ( C O N T o ) C h a r a c t e r s "laxum" h e t e r o s - s u d e t i c u m b r e v i p e s t i c h u m ^ — Len g t h o f s e t a 4-5 mm 4-7 mm 3-3.5 mm 4-7 mm C a p s u l e c y l i n d r i c ( C ) , o v o i d (c) C C c C Le n g t h o f c a p s u l e 1.5-2.8 cm 1.8-2.7 mm 0.6-2 mm 2-3 mm Upper e x o t h e c i a l c e l l s round ( R ) , f l a t r e c t a n g u l a r ( r ) R R R Le n g t h o f p e r i s t o m e t e e t h 0.4 mm 0.2-0.35mm 0.3 mm 0.3 mm T r a n s v e r s e b a n d i n g i n p e r i s t o m e t e e t h v e r y prominent ( T ) , not t T t t pro m i n e n t ( t ) Branches o f p e r i s t o m e t e e t h u s u a l l y j o i n e d a t v a r i o u s p l a c e s ( B ) , b-B b-B b b-B f r e e (b) Branches more o r l e s s e q u a l i n s i z e ( E ) , n ot e q u a l (e) e-E Le n g t h o f operculum 0.8 mm 1 mm 1 mm 1 mm Len g t h o f c a l y p t r a 1.2-1.8 mm - 1-1.2 mm 2 mm Dimension o f s p o r e s 12-13 /u 12-18 AX 12-15 n 12-15 AX 44 DISCUSS.ION I n t r e a t i n g any group o f a p p a r e n t l y r e l a t e d s p e c i e s an a t t e m p t i s made t o s e l e c t t h o s e c h a r a c t e r s t h a t a re assumed t o be g e n e t i c a l l y c o n t r o l l e d and a r e n o t g r e a t l y m o d i f i e d by e n v i r o n m e n t a l d i f f e r e n c e s . The gametophyte i n s e v e r a l b r y o p h y t e s i s m a r k e d l y a l t e r e d by e n v i r o n m e n t a l change, p a r t i c u l a r l y changes i n moisture- a v a i l a b l e t o t h e p l a n t . Buch (1919, 1920) n o t e d a c o n s p i c u o u s p h e n o t y p i c r e s p o n s e i n s p e c i e s o f s e v e r a l h e p a t i c g e n e r a . Lodge (1959, 1960) n o t e d g r o s s m o r p h o l o g i c a l changes i n t h e moss, genus D r e p a n o c l a d u s , a l t h o u g h t h e a r e o l a t i o n o f t h e l e a v e s remained c o n s t a n t , t h u s t h e r e c o g n i z e d s p e c i e s were c o n s i d e r e d g e n e t i c a l l y d i s t i n c t . I n R h a c o m i t r i u m t h e n a t u r e o f t h e b r a n c h i n g p a t t e r n appears t o be h i g h l y p l a s t i c , and i t i s p o s s i b l e t h a t t h e n a t u r e o f t h e h a i r p o i n t and t h e upper l e a f c e l l s a r e a l s o a f f e c t e d by m o i s t u r e c o n d i t i o n s . Kawai (1965) has s u g g e s t e d such a - c o r r e l a t i o n i n t h e c l o s e l y r e l a t e d genus Grimmia. U n f o r t u n a t e -l y t h e s e c h a r a c t e r s a r e u t i l i z e d t o s e p a r a t e t h e v a r i o u s t a x a i n t h e R h a c o m i t r i u m h e t e r o s t i c h u m complex. Thus any at t e m p t t o s e p a r a t e t h e v a r i o u s e l e m e n t s o f t h e Ro h e t e r o s t i c h u m complex must be h i g h l y t e n t a t i v e , and a number o f r e a s o n a b l e arrangements a r e p o s s i b l e . I n T a b l e I a c o m p a r i s o n i s made among a l l t a x a c o n s i d e r e d i n t h e p r e s e n t s t u d y . An a t t e m p t has been made t o group t h o s e i n d i v i d u a l s o f g r e a t e s t s i m i l a r i t y t o g e t h e r . I n 45 o r d e r t o do so a c e r t a i n b i a s i s n e c e s s a r y and c e r t a i n assump-t i o n s a r e made. The most b a s i c a s s u m p t i o n i s t h a t a number o f t h e c h a r a c t e r s a r e g e n e t i c a l l y c o n t r o l l e d and are t h u s v a l i d c r i t e r i a t o u t i l i z e i n r e c o g n i t i o n o f a t a x o n . A second a s s u m p t i o n i s t h a t t h e c o n d i t i o n s o f a l p i n e v e r s u s n o n - a l p i n e e n v i r o n m e n t have s e r v e d t o s e l e c t o u t g e n e t i c a l l y d i s t i n c t t a x a and t h a t a v e r y p l a s t i c s p e c i e s i s n o t i n v o l v e d . I n one c a s e v a r i o u s t a x a a r e i n v o l v e d , w h i l e i n t h e o t h e r a s i n g l e t a x o n i s i n v o l v e d , p r o d u c i n g a d i f f e r e n t phenotype i n d i f f e r i n g e n v i r o n m e n t s . Thus R. s u d e t i c u m i s c o n s i d e r e d a s p e c i e s r e s t r i c t e d t o a r c t i c and a l p i n e e n v i r o n m e n t s w h i l e R. h e t e r o s t i -chum i s e s s e n t i a l l y o f l o w e r e l e v a t i o n s , a t l e a s t i n B r i t i s h C o l u m b i a . Both R. "laxum" and R. b r e v i p e s show a w i d e r e n v i r o n -m e n t a l r a n g e . U s i n g t h e s e a s s u m p t i o n s t h e f o l l o w i n g s e g r e g a -t i o n has been made f o r t h e R. h e t e r o s t i c h u m complex i n B r i t i s h C o l u m b i a ^ F o u r s p e c i e s a r e i n v o l v e d : R. "laxum", R. h e t e r o s t i c h u m , b r e v i p e s and R. s u d e t i c u m . V a r i a t i o n w i t h i n t h e s e s p e c i e s i s r e p r e s e n t e d by R. h e t e r o s t i c h u m v a r . a f f i n e , R. s u d e t i c u m v a r . m a c o u n i i and R. b r e v i p e s v a r . " l a e v i s " , v a r . "eramulosum" and v a r . " m i c r o c a r p i f o r m i s " . W i t h i n t h e s p e c i e s o t h e r minor v a r i a t i o n o c c u r s . The n o m e n c l a t u r e o f t a x a w i t h i n t h e complex i s g r e a t l y c o m p l i c a t e d because many names ar e a v a i l a b l e . U n t i l t h e s e a v a i l a b l e names a r e e v a l u a t e d i t would be f o o l h a r d y t o a p p l y any t o t h e t a x a r e c o g n i z e d i n t h i s s t u d y . I t would be e q u a l l y h a z a r d o u s t o i n t r o d u c e f u r t h e r new names w i t h o u t t h o r o u g h l y a s s e s s i n g t h o s e a v a i l a b l e . 4 6 To come c l o s e r t o an a c c e p t a b l e s o l u t i o n t o t h e n a t u r e o f t h e t a x a w i t h i n t h e R. h e t e r o s t i c h u m complex a number o f f u r t h e r s t e p s a r e s u g g e s t e d . F i r s t , r e c i p r o c a l t r a n s p l a n t a -t i o n s h o u l d be made o f t h e presumed t a x a o f t h e complex t o c o n t r a s t i n g e n v i r o n m e n t s . These p o p u l a t i o n s s h o u l d be l e f t t o grow f o r s e v e r a l y e a r s t o n o t e t h e p h e n o t y p i c r e s p o n s e , assuming t h a t t h e y s u r v i v e i n t h e new e n v i r o n m e n t . Second, a number o f t h e t a x a c o u l d be grown t o g e t h e r under c o n t r o l l e d m o i s t u r e and l i g h t c o n d i t i o n s and changes i n morphology n o t e d . T h i r d , a. r e l a t i v e l y s i m p l e e x p e r i m e n t might d e t e r m i n e whether g r e a t l y i n c r e a s e d m o i s t u r e made a v a i l a b l e t o a g r o w i n g gametophyte o f any t a x o n i n t h i s complex would r e s u l t i n changes i n t h e n a t u r e o f t h e h a i r p o i n t o r t h e n a t u r e o f t h e upper l e a f c e l l s . F o u r t h , specimens from a c o n s i d e r a b l y w i d e r g e o g r a p h i c r ange s h o u l d be examined t o n o t e t h e t o t a l v a r i a t i o n i n t h i s s p e c i e s complex t h r o u g h o u t i t s r a n g e . T h i s would be a r a t h e r e x t e n s i v e u n d e r t a k i n g s i n c e t h e complex has an e x t r e m e l y wide g e o g r a p h i c range and shows c o n s i d e r a b l e d i v e r s i t y t h r o u g h t h i s r a n g e . 47 BIBLIOGRAPHY A n d e r s o n , L„E„ 1954 0 H o y e r 1 s s o l u t i o n as a r a p i d permanent medium f o r b r y o p h y t e s . B r y o l o g i s t . 5_7: 242-244. A n d e r s o n , L.E. 1958. The mosses o f N o r t h C a r o l i n a . V I I B r y o l o g i s t . 51:. 293-296. A u g i e r , J . 1966. F l o r e des B r y o p h y t e s . E n c y c l o p e d i e B i o l o g i q u e LXIV: 1-702. L e c h e v a l i e r , P a r i s . B r i d e l , S.E. 1819. M u s c o l o g i a e R e c e n t i o r u m Supplementum, P a r s I V Seu M a n t i s s a Generum specierumque Muscorum Frondosorum U n i v e r s a a sam. E l . a. B r i d e l I - X V I I I + 222 pp. S e c o n d " i s s u e Gotha, Germany: U k e r t . Buch, H. 1919. Uber den E i n f l u s s von L i c h t und F e u c h t i g k e i t auf d i e Wa c h s t u m s r i c h t u n g d e r Lebermoosgametophyten. Ov e r s . E i n s k . V e t e n s k . Soc. F o r h . 6JL: 1-8. Buch, H. 1920. P h y s i o l o g i s c h e und" e x p e r i m e n t e l l - m o r p h o l o g i e s.tudien an b e b l a t t e r n Lebermoosen I - I I . O v e r s . Finsk„ V e t e n s k . Soc. F o r h . 6_2: 1-46. Crum, W.A., W.C. S t e e r e and L.E. And e r s o n . 1965. A. l i s t o f the mosses o f N o r t h A m e r i c a . B r y o l o g i s t 68: 377-432. de S l o o v e r , J . L . and F. Demaret. 1968. F l o r e G e n e r a l e de B e l g i q u e B r y o p h y t e s . V o l . I l l , F a s c . I . B r u x e l l e s , 1-112. D i x o n , H.N. 1924. The S t u d e n t s Handbook o f B r i t i s h Mosses., Wheldon & Wesley L t d . , London. I - XLVI + 582 + ; 63 p l a t e s . F r y e , T.C. 1918. The R h a c o m i t r i u m o f Western N o r t h A m e r i c a . B r y o l o g i s t 2_1:. 3-15, p i s . I I - V I . J o n e s , G.N. 1933. R h a c o m i t r i u m B r i d . i n Moss f l o r a o f N o r t h A m e r i c a by A . J . G r o u t , v o l . I I . Vermont. 50-58, p l a t e s XXI and X X I I . . K a w a i , I . 1965. S t u d i e s on t h e genus Grimmia, w i t h r e f e r e n c e t o t h e a f f i n i t y o f t h e gametophyte. S c i . r e p o r t s , Kanazawa U n i v . JLO: 79-132 , 54 p l a t e s . Lodge,. E. 1959. E f f e c t s o f c e r t a i n c u l t i v a t i o n t r e a t m e n t s on t h e morphology o f some B r i t i s h s p e c i e s o f D r e p a n o c l a d u s . J . L i n n . Soc. London. (Botany) 56: 218-244. 48 Lodge, E.. 1960. S t u d i e s o f v a r i a t i o n i n B r i t i s h m a t e r i a l o f D r e p a n o c l a d u s f l u i t a n s and Prepanoc1adus  e x a n n u l a t u s . Slvens B o t . T i d s k r . 54: 368-393. M a r t e n s s o n , O. 1956. B r y o p h y t e s o f t h e T o r n e t r a s k a r e a , N o r t h e r n Swedish L a p p l a n d I I . M u s c i . K o n g l . Svenska Vetens KapsaJcad. H a n d l . 14: 1-321. Nyholm, E:. 1956. I l l u s t r a t e d Moss F l o r a - o f E e n n o s c a n d i a I I M u s c i . F a s c . I I . 85-189. G l e e r u p , Lund, Sweden. P e r s s o n , H„ 1947. F u r t h e r n o t e s on Alarsk an-Yukon b r y o p h y t e s . B r y o l o g i s t 50: 305-307. R e n a u l d , E. and J . C'ardot. 1890. New Mosses o f N o r t h A m e r i c a . B o t . Gaz. 15: 39-45. W i j k , V. D., W.D. Margadant and P.A--. F l o r s c h u t z . 1967. Index Muscorum IV. 604 pp. U t r e c h t , N e t h e r l a n d s . APPENDIX R. "laxum" Figures 1 & 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 P L A T E I Habit showing branching pattern (X 1.5) Hyaline point of leaf (X 280) C e l l s from lower portion of l e a f (X 280) Sporophytes (X 5) Costa from upper portion of leaf (X 280) C e l l s from just below hyaline point of le a f (X 280). PLATE II R. "laxum" Figure 1 - Cross section from lower portion of leaf (X 280) Figure 2 - Cross section from middle portion of leaf (X 280) Figure 3 - Stomate (X 1120) Figure 4 - Spores (X 1120) Figure 5 - Cross section from upper of leaf just below hair point (X 280) Figure 6 - Portion of annulus (X 280) Figure 7 - Cross section from middle portion of the leaf showing b i s t r a t o s e margin (X 280) Figure 8 - Cross section from lower edge of upper 1/3 of leaf (X 280). PLATE I I I Ro "laxum" Figure 1 - Peristome teeth showing p a p i l l o s i t y (X 1120) Figure 2 - Upper exothecial c e l l s (X 1120) Figure 3 - Peristome teeth (X 280) Figure 4 - Exothecial c e l l s from middle of capsule wall (X 280). PLATE IV R. h e t e r o s t i c h u m F i g u r e s 1 & 2 F i g u r e 3 F i g u r e 4 F i g u r e 5 F i g u r e 6 F i g u r e 7 H a b i t showing b r a n c h i n g p a t t e r n (X 1«, 5 ) M i d d l e p o r t i o n o f t h e l e a f showing c o s t a (X 2 8 0 ) C e l l s from upper p o r t i o n o f l e a f (X 2 8 0 ) H y a l i n e p o i n t o f l e a f (X 2 8 0 ) C e l l s from l o w e r p o r t i o n o f l e a f (X 2 8 0 ) C e l l s from m i d d l e p o r t i o n o f l e a f (X 2 8 0 ) P L A T E V R. h e t e r o s t i c h u m F i g u r e 1 - C r o s s s e c t i o n from upper p a r t o f l e a f , j u s t ; below h y a l i n e p o i n t (X 280) F i g u r e 2 - C r o s s s e c t i o n from n e a r base o f l e a f (X 280) F i g u r e 3 - C r o s s s e c t i o n f rom bottom edge o f upper 1/3 o f l e a f (X 280) F i g u r e 4 - C r o s s s e c t i o n from upper edge o f l o w e r 1/3 o f l e a f (X 280) F i g u r e 5 - Operculum (X 110) F i g u r e 6 - S p o r o p h y t e s (X 5) F i g u r e 7 - Spores (X 1120). PLATE VI R. heterostichum Figure 1 - Peristome teeth (X 280) Figure 2 - Sporophytes of R. heterostichum var. a f f i n e (X 5) ~~ Figure 3 - Peristome teeth showing p a p i l l o s i t y (X 1120) Figure 4 - Exothecial c e l l s from middle of capsule (X 280) Figure 5 - Cross section from upper portion of leaf just below hyaline point (X 280) Figure 6 - Stomate (X 1120) Figure 7 - Portion of annulus (X 280). P L A T E V I I R. h e t e r o s t i c h u m v a r . a f f i n e F i g u r e 1 - H a b i t showing b r a n c h i n g p a t t e r n (X 1.5) F i g u r e s 2 & 4 - C r o s s s e c t i o n from upper p o r t i o n o f l e a f (X 280) F i g u r e 3 - C r o s s s e c t i o n from n e a r base o f l e a f (X 280) F i g u r e s 5 & 6 - C r o s s s e c t i o n from m i d d l e p o r t i o n o f l e a f (X 2 8 0 ) . PLATE VIII R, s u d e t i c u m F i g u r e s 1 & 2 - H a b i t showing b r a n c h i n g p a t t e r n (X 1.5) F i g u r e 3 - C e l l s from upper p o r t i o n o f l e a f (X 280) F i g u r e 4 - C e l l s from m i d d l e p o r t i o n o f l e a f (X 280) F i g u r e 5 - C e l l s f r om l o w e r 1/3 o f l e a f (X 280) F i g u r e 6 - H y a l i n e p o i n t o f l e a f showing d e n t i c u l a t i o n b o t h on t h e m a r g i n and on t h e s u r f a c e (X 2 8 0 ) . PLATE IX R. sudeticum Figure 1 - Cross section from upper portion of leaf just below hyaline point (X 280) Figure 2 - Cross section from lower edge of upper 1/5 of leaf (X 280) Figure 3 - Cross section from lower edge of upper 1/3 of le a f (X 280) Figure 4 - Cross section from near base of leaf (the lower section). (X 280) Figure 5 - Sporophytes (X 5) Figure 6 - Peristome teeth ( X 280) Figure 7 - Portion of annulus (X 280) Figure 8 - Spores (X 1120) Figure 9 - Peristome teeth showing p a p i l l o s i t y (X. 1120). PLATE X R„ sudeticum var. macounii Figures 1 & 2 - Habit showing branching pattern (X 1„5) Figure 3 - Upper portion of leaf showing leaf c e l l s and short hyaline point (X 280) Figure 4 - Sporophytes (X 5) Figure 5 - C e l l s from middle portion of l e a f (X 280) Figure 6 - Leaf apex showing absence of hyaline point (X 1120) Figure 7 - C e l l s of leaf base (X 280) Figure 8 - Operculum of R. sudeticum (X 110} 0 PLATE XI brevipes Figures 1 & 2 - Habit showing branching pattern (X 1.5 Figure 3 - Leaf apex showing strongly denticulate hyaline point (X 280) Figure 4 - C e l l s from lower 1/3 of leaf (X: 280) Figure 5 - C e l l s from upper 1/3 of l e a f (X. 280) Figure 6 - C e l l s from near middle of leaf (X: 280) PLATE. XII R. brevipes; Figure 1 Figure 2 Figures 3 & 5 Figure 4 Figure 6 Figure. 7 Sporophytes (X 5) Cross section from near base of leaf showing costa (X: 280) Cross, section from upper 1/3 of leaf (X 280) Cross: section from near base of leaf showing margin (X 280) Cross section from middle portion of le a f (X 280) Operculum (X 160). PLATE XIII R. brevipes Figure 1 - Peristome teeth (X 280) Figure 2 - Lower portion of capsule showing stomates (X 280) Figure 3 - Exothecial c e l l s near mouth of capsule (X"280) Figure 4 - Portion of annulus (X 280) Figure 5 - Operculum (X 110) Figure 6 - Upper portion of Calyptra (X: 110) Figure 7 - Sporophytes of R. brevipes var. "microcarpif ormis" (X. 4). PLATE XIV brevipes var. " l a e v i s " Figure 1 - Habit showing branching pattern (X 1. Figures 2 & 5 - Cross section from lower 1/3 of leaf (X 280) Figures 3,4 & 6 - Cross section from middle portion of leaf (X 280). PLATE. XV brevipes var. "eramulosum" Figure 1 - Habit showing branching pattern (X 1.5) Figure 2 - Sporophytes (X 5) brevipes var. "microcarpiformis" Figure 3 - C e l l s from just below hyaline point of leaf (X- 280") Figure 4 - Habit showing branching pattern (X 1.5) Figure 5 - C e l l s from middle portion of leaf (X 1120) Figure 6 - C e l l s from lower portion of leaf (X 1120). PLATE XVI R„ brevipes var. "microcarpiformis" Figure 1 - Cross section from lower edge of upper 1/3 of leaf (X 280) Figures 2 & 4 - Gross section from middle portion of lea f (X 280) Figure 3 - Cross section from lower 1/3 of leaf (X 280) Figure 5 - Exothecial c e l l s from middle of capsule wall (X. 280) Figure 6 - Spores (X 1120). PLATE XVII Leaves of R.. "laxum" (X 48) PLATE XVIII Figures 1 & 3 -Leaves of R. heterostichum (X 48) Figure 4 -Leaf of R. heterostichum var. a f f i n e (X 48). PLATE XIX Figures 1 - 4 - Leaves of R. sudeticum (X 48) PLATE XX Figures 1 - 3 - Leaves of R. sudeticum var. macounii (X 48) PLATE XXI Figures 1 & 2 - Leaves of R. brevipes (X 48) Figures 3 & 4 - Leaves of R. brevipes var. "laevis"' (X 48) PLATE XXII F i g u r e 1 - Leaves of R. b r e v i p e s v a r . "eramulosum" (X 48) F i g u r e s 2 - 4 - Leaves of R. brev i p e s v a r . " m i c r o c a r p i f o r m i s " 

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