44 BRYACE^. [Pleurldium. 



* * Floioers monoecious / 9?iale plants gemmifonn, axillari/. 



3. P. altsrnifolium, Brid., in pai-t. Plants cespitose, at 

 first simple and erect, after a year becoming prostrate and 



• brancliinof in lona: ila2:elliform innovations : comal leaves 

 enlarged at the ovate base, abruptly narrowed into a slender 

 awl-shaped slightly serrulate jDoint, filled by the stout ex- 

 curreut costa : capsule ovate or subglobose, obliquely apiculate : 

 calyptra split to near the acuminate ai^ex. — Bryol. Eur. t. 10. 

 jPkascum alternifoliu7n, Sulliv. Mosses of U. States, 15. 



Var. Lancastriense, Sulliv. & Lesq. Leaves longer ; 

 areolation more dense : capsule more obtuse ; spores larger. — ■ 

 Muse. Bor.-Am. Exsicc. (ed. 1), n. 30. 



Var. robustuin, Sulliv. & Lesq. Plants twice as long as in 

 the common form: comal leaves shorter: spores large. — Same, 

 n. 31. Archidium Lescurii, Aust. Bull. Torr. Club, vi. 144. 



Hab. Open fields, on sandy and clayey ground; very common. 



The first variety at Lancaster, Ohio, with Bruchia SuUlvantii ; the last 

 on the Raccoon Mountains, Alabama, in humid depressions on sandstone 

 rocks, with Bruchia Sullivantii, var. nigricans {Lesquereux}. 



4. P. Sullivantii, Aust. Plants gregarious : stems rigid, 

 julaceous ; innovations filiform, nearly as long as the stems : 

 leaves closely imbricate and appressed, the lower ovate- 

 mucronate, denticulate, the upper enlarged, longer pointed, 

 obscurely serrate ; perichaetial leaves much longer, oblong-ovate, 

 abruptly cuspidate, erose-serrate above ; costa thick, percurrent 

 or excurrent : capsule large, round-ovate, short-i^edicellate, ob- 

 tusely mamillate ; calyptra large, campanulate, obtusely acumin- 

 ate. — Bull. Torr. Club, vi. 142. Pliascum nervosum^ Drumm. 

 Coll. n. 6; Sulliv. Mosses of IT. States, 16. Pleuridium ner- 

 vosum^ Sulliv. Icon. Muse. 19, t. 10. 



Hac. Pennsylvania [I)nimmond)\ South Carolina, on light sandy soil 

 [RaveneX). Phascum nervosum, Hook., a species of the Cape of Good 

 Hope, is evidently different. 



5. P. Bolanderi, Muell. Leaves long-lanceolate and subu- 

 late, minutely denticulate from the middle upward, with a pale 

 excurrent costa : capsule ovate, obliquely apiculate, short- 

 pedicellate ; calyptra dimidiate, often split, blackened at the 

 apex. — Jaeger, Muse. Cleist. 32. 



Hab. Near San Francisco, California {Bolander). 



Distinguished from other species of the genus by the leaves obscurely 

 serrulate from the middle upward, by the pale costa, the short-pedicellate 

 capsule, and the top of the calyptra appearing as if burned. 



( 



