Pottia.] BEYACE^. 101 



round, rarely lamellose toward the apex. Capsule erect. 

 Peristome either none or very imperfect, or composed of 16 flat 

 teeth. 



* Ccqjside without jjeristome or nearly so. 



1. P. cavifolia, Ehrh. Leaves ovate-oblong, very concave, 

 long-aristate by the excurrent lamellate costa : capsule exserted, 

 ovate-oblong, — Beitr. i. 187; Bryol. Eur. t. 118. Gymnosto- 

 tnum ovatwn, Hedw. Muse. Frond, i. 15, t. 6. Pottia pusilla, 

 Lindb. Trichost. 218. 



Hab. On naked ground ; Platte River, at base of the Rocky Moun- 

 tains (E. Uall); Fort Colville {Lyall}; near Carson City, Nevada 

 ( Watson). 



Tlie leaves are sometimes scarcely aristate and the plants in loose tufts, 

 sometimes with a very long white hair and the plants very densely 

 cespitose. 



2. P. minutula, Fuern. Plants minute, annual : leaves 

 open, ovate and oblong-lanceolate, cus])idate by the excurrent 

 brown costa, recurved on the borders, minutely papillose on the 

 back, reddish when old : anthers naked in the axils of perichae- 

 tial or in buds composed of two small perigonial leaves : cap- 

 sule minute, ovate, truncate ; lid broad, short, conical-obtuse. — 

 Regensb. Flora, xii, Erg.-bl. 10; Bryol. Eur. 1. 119. Gyynnosto- 

 mwn mimctulum, Schwaegr. Suppl. L 25, t. 9. P. StarJcei^ var. 

 gymno stoma., Lindb. Trichost. 219. 



Hab. Los Angeles, California (Bigelow)', very rare in America, com- 

 mon in Europe. 



3. P. truncata, Fuern. 1. c. Plants small and simple, or 

 longer and ramose, gregarious or subcespitose : leaves open, 

 oblong or obovate, acuminate and mucronate by the excurrent 

 costa, soft, loosely areolate, concave, flat on the borders, nearly 

 smooth : capsule broadly ovate, truncate or subcylindrical, 

 gymnostome ; lid plano-convex, obliquely rostellate, attached to 

 the columella and falling with it. — Bryol. Eur. t. 120, 121. 

 Pryiitn truncatulum^ Linn. Spec. PI. 1119. Gymnostomum 

 truncatum, Hedw. Muse. Frond, i. 13, t. 5. P. eustoma, Ehrh. 

 Beitr. i. 187. 



Hab. Open ground; New England to Pennsylvania. 



4. P. Wilsoni, Bruch & Schimp, Plants simple, loosely 

 cespitose : leaves close, gradually larger upwards, open, erect, 

 oval-oblong or ovate-spathulate, rounded at the apex and cuspi- 



