Jennings: Manual of Mosses 19 



BraCHY THECIACEAE ( 1 20- 1 26 ) 



120. Capsule erect to horizontal, symmetric to unsymmetric; basal membrane 



low !20a 



120. Capsule generally inclined or horizontal, unsymmetric; basal membrane 



high - 121 



120a. Calyptra hairy; segments adhering to peristome-teeth 



Homa'otheciella, p. 286 



120a. Calyptra smooth; segments not adhering to peristome-teeth (^ee also 



Brachythecium ) Chamberlainia, p. 287 



121. Leaves with several deep plications spoon-shaped; branches i'.daceous 



C amptolhecium , p. 287 



121. Leaves plane or but shallowly plicare 122 



122. Operculum conic, sometimes short-rostrate; alar cells difFerenciited, quad- 

 rate; capsules usually short, thick, dark chestnut color. (If leaves 



dorsally papillose, see Bryhnia) Brachythecium, p. 289 



122. Operculum long rostrate; alar cells few or not differentiated 123 



123. Autoicous; branches and leaves complanate, leaves mostly only slightly con- 

 cave, never sulcate, ovate to ovate-linceolate, more or less acuminate; 

 costa rarely ending in a spine on the back of the leaf; cells narrow, smooth; 



seta smooth Rhynchostegium, p. 306 



123. Dioicous; seta generally papillose; costa sometimes ending in a spine on the 



back of the leaf; leaves not complanate 124 



124. Leaves very concave, not at all or but weakly plicate, ovate to oblong, 

 more or less abruptly acuminate or piliferous; costa not ending in a 



spine; cells mrrow and smooth Cirriphylltim, p. 293 



124. Not with the characters combined as above 125 



125. Stem and branch-leaves often dissimilar, stem-leaves ovate- to triangular- 

 cordate or rounded triangular-oval, obtuse to somewhat acuminate; costa 



often ending in a spine; leaf-cells very narrow and smooth 126 



125. Stem-leaves more or less concave, irregularly plicate; cells elongated-rhomboid 

 to elongated-hexagonal; branch-leaves rough on the back by papillae or 



tooth-like projecting cell-angles; seta very rough Bryhnia, p. 304 



126. Leaves not or very little concave, never plicate; seta smooth or rough 



Oxyrhynchium, p. 300 



126. Leaves more or less concave, indistinctly plicate; seta smooth 



Eurhynchium, p. 302 



127. Mostly not aquatic, sometimes submerged but yet floating Fissidens, p. 69 



127. Aquatic, filiform, and floating Octodiceras, p. 75 



128. Leaves obtuse 129 



128. Leaves acute to acuminate - 130 



129. Aquatic, usually m streams; leaves spreading or somewhat secund, soft and 



thin; branching irregular Hygrohypnum, p. 243 



129. In bogs or swamps; glossy; regularly pinnate; leaves loosely appressed or 



descending Calliergoriella, p. 242 



130. Leaves squarrose to squarrose-recurved (see also Plagiothecium) 



Campylium, p. 247 



130. Leaves otherwise 13 1 



131. Alar cells inflated; leaves deirurrent Plagiothecium striatellum, p. 275 



131. Alar cells not inflated 132 



132. Median leaf-cells linear-hexagonal, about 4-8:1, the apical shorter and 

 sub-rhomboidal, the alar quadrate and green-opaque, incrassate: leaves 

 about 0.6-1.0 mm long Homomallium, p. 225 



132. Leaves decurrent; median leaf-cells linear, 5-15:1 Plagiothecium, p. 274 



132. Leaves not decurrent; median leaf-cells linear, 20:1 



Isopterygium ptilchellum, p. 272 



