286 American Midland Naturalist Monograph No. 6 



less dorsally rough 8. Bryhnia 



E. Leaves complanate (Also see Oxyrrhynchium) 9. Rhynchostegium 



E. Leaves imbricated or spreading F 



F. Leaves deeply concave, spoon-like abruptly piliferous-acuminatc 5. Cirriphyllum 



F. Leaves plane or somewhat concave, acute or gradually acuminate, not piliferous G 



G. Leaves not much concave, non-plicate 6. Oxyrhynchium 



G. Leaves mostly distinctly concave and plicate 7. Eurhynchiutn 



H. Calyptra hairy; segments adhering to the peristome-teeth 1. Homalotheciella 



H. Calyptra smooth; segments not adhering to the peristome-teeth. (See also some 



species of Brachythecium) 3. Chamberlainia 



1. Homalotheciella (Cardot) Brotherus 



Autoicous: 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 imbricate, when moist erect-spreading, non-decurrent, non-plicate, con- 

 cave, oval to oblong, the apex acuminate to lancc-subulate, upper half of leaf 

 serrulate to entire; coGta simple, sometim.es reaching to mid-leaf; median leaf- 

 cells oblong-elliptic, thin, smooth, the alar green, numerous, quadrate; inner 

 perichaetial leaves abruptly serrate-subulate from a sheathing base; seta about 

 7 mm long, castaneous, rough; capsule erect to almost horizontal, more or less 

 unsymmetric, oblong, drying 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, adherent 

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



A small genus of three (4) North American species, one species occurring 

 in our range. 



1. Homalotheciella subcapillata (Hedwig) Cardot 



(Pterigynandrum suhcapillatum Hedwig; Homalothecium subcapillatum 

 SuUivant; Platygyrium brachycladon Kindberg) 



Forming light green, thin, glossy mats: stems prostrate, irregularly branch- 

 ing; leaves loosely imbricate when dry, elliptic-oblong, abruptly long-acumin- 

 nate, more or less serrate above, about 0.9-L2 mm long, concave, non-plicate, 

 not papillose; costa usually reaching about to the middle of the leaf; median 

 leaf-cells, about 8-10:1, fusiform-elliotic, towards the apex somewhat shorter, 

 the alar quadrate, numerous and forming a group which extends upwards 

 along the margin to often one-third the length of the leaf; inner perichaetial 

 leaves sheathing, long-acuminate: seta rough, about 6-9 mm long, slender; 

 capsule about 2-3.5:1, sub-erect, slightly incurved, dorsally somewhat gibbous, 

 slightly constricted below the mouth when dry; operculum conic or convex; 

 annulus 2-seriate; peristome-teth confluent at base, dark red, with a broad 

 pellucid central stripe marked by a delicate medial line, the segments adhering 

 to and lining the teeth inside, forming a hyaline border; spores mature in 

 autumn, about .025 mm. 



