BRYACEAE 65 



With the exception of Rhodobryum, Leptobryum, Plagio- 

 bryum, Bryum argenteum and possibly Mniobryum, it is ex- 

 tremely difficult to determine species of this subfamily unless 

 perfect fruiting specimens can be obtained. It will be a dis- 

 couraging task to any one except a specialist in the group, and 

 one not worth while under any ordinary circumstances. 



LEPTOBRYUM Schimp. 



L. pyriforme (L.) Wils. Moist cliffs and stones, fields and 

 mortar in basement walls of houses and ( walls; also greenhouses; 

 frequent. June-July. 



POHLIA Hedw. 



Plants tufted, usually growing on moist soil and stones. 

 Lower leaves shorter, ovate-lanceolate as a rule, the upper 

 longer, the comal usually linear-lanceolate; costa ending just 

 below apex, percurrent or rarely excurrent; leaf cells narrowly 

 rhomboidal to linear; capsule pear-shaped or clavate, usually 

 with a proportionately long tapering neck; cilia of inner peris- 

 tome not appendiculate. 



This subgenus is sometimes treated as a subgenus of Bryum, 

 from which it differs in little except the narrower areolation and 

 narrower comal leaves. 



1 — Capsules very short and small; stems not red Lescuriana 



Capsules larger and longer; stems often red when old 2 



2 — Bearing gemmae in the axils of the leaves of the sterile stems; dioi- 



cous; infrequent or rare proligera 



Not producing gemmae; never wholly dioicous, sometimes polygamous. 3 

 3 — Infrequent, growing principally in the mountains; leaf cells very 

 long and narrow, linear-vermicular, 11-16: 1; lower leaves large, 



broadly ovate cruda 



Common everywhere; leaf cells broader; lower leaves smaller than in 

 cruda, ovate nutans 



P. cruda (L.) Lindb. Alpine, N. J., Austin; Yonkers, South- 

 worth; Kreischerville, S. Id., E. G. B., all at Bx! 



P. Lescuriana (Sulliv.) Grout. "On banks along roadsides, 

 Palisades, northern N. J. and southern N. Y.," Muse. App. 

 190; frequent on Staten Island!! Spring. 



