330 A MANUAL OF MOSSES 



Key to the Genera. 

 a. Capsule erect and symmetric; basal membrane mostly low. 



1. Hotnalotheciella. 

 a. Capsule cernuous to horizontal, unsymmetric; basal membrane 

 mostly high. b. 



b. Leaves with several deep plications. 2. Camptothecium. 

 b. Leaves not deeply plicate. c. 



c. Lid conic, sometimes acute; alar cells differentiated. 



3. Brachythecium. 

 c. Lid long-rostrate; alar cells few or none. d. 

 d. Cells narrow, smooth. e. 



d. Cells oblong-rhomboidal to oblong-hexagonal, those of the 

 branch-leaves more or less rough dorsally. 



7. Bryhnia. 

 e. Leaves complanate. 8. Rhynchostegium. 



e. Leaves imbricated or spreading. f. 



f. Leaves deeply concave, spoon-like, abruptly piliferous-acumi- 



nate. 4. Cirriphyllum. 



f. Leaves plane or somewhat concave, acute or gradually acumi- 

 nate, not piliferous. g. 

 g. Seta smooth in our species; leaves not much concave, nonplicate. 



5. Oxyrrhynchium. 

 g. Seta rough or smooth: leaves mostly concave and plicate. 



6. Burhynchium. 



1. HOMALOTHECIBLLA (Cardot) Brotherus. 



Auloicous : slender, soft, laxly cespitose, green, lustrous : 

 stem creeping, elongate, beset thickly with obtuse, short, 

 ascending to erect, densely-leaved branches which are often 

 arcuate when dry ; paraphyllia none ; when dry the leaves im- 

 bricate, when moist erect-spreading, non-decurrent, non- 

 plicate, concave, oval to oblong, the apex acuminate to lance- 

 subulate, upper half of leaf serrulate to entire ; costa simple, 

 sometimes reaching to mid-leaf; median leaf-cells oblong- 

 elliptic, thin, smooth, the alar green, numerous, quadrate; 

 inner perichsetial leaves abruptly serrate-subulate from a 

 sheathing base ; seta about 7 mm. long, castaneous, rough ; 

 capsule erect to sub-erect, weakly unsymmetric, oblong, dry- 

 ing somewhat constricted below the mouth and often sub- 

 arcuate ; annulus present ; inner peristome much shorter than 

 the outer, teeth basally confluent, lance-linear, dorsally cross- 

 striate, apically papillose, lamellae laterally projecting; inner 

 peristome somewhat united with the outer, yellow, smooth, 

 with low basal membrane, segments short, narrow, entire, 

 cilia none ; lid long-rostrate ; calyptra slightly hairy at base. 



A small genus of three North American species ; one 

 .species occurring in our range. 



1. Homalotheciella subcapillata (Hedwig) Brotherus. 

 (Pterigynandruin subcapillatuni Hedwig; Homalothecium sub- 



capillatum Sullivant). 



Forming light green, thin, glossy mats : stems prostrate, 

 irregularly branching; leaves loosely imbricate when dry. 



