Hypnum.] BRYACE^. 345 



Scand. 35. IT. chrysostomum, Muell. Syn. ii. 368, not Michx. 

 Brachythecium rivulare, Bruch & Schimj). Bryol. Eur. t. 546. 



Hab. Swamps and wet ground, in woods and mountains; not com- 

 mon. N. W. Montana (TFaison). 



Resembles //. rutabulum, but the brandies are stronger, divided near 

 the apex and often dendroid, the leaves broader, glossy, short-acuminate, 

 and not plicate, flowers dioecious, etc. 



57. H. populeum, Hedw. Monoecious : tufts flat, green, 

 somewhat glossy ; stems creeping ; branches and branchlets 

 erect or incurved, attenuate at the apex : leaves ovate and ob- 

 long, lanceolate, gradually long-acuminate, concave ; borders 

 flat, serrulate upward ; costa percurrent ; areolation very nar- 

 row ; alar and basilar cells larger, quadrangular-oblong : calyp- 

 tra large : capsule cernuous, ovate, turgid or gibbous, inflated 

 at the neck, glossy, contracted under the orifice when empty ; 

 pedicel purple, slightly scabrous above, smooth toward the base ; 

 segments split ; cilia one or two, short or unequal, appendicu- 

 late ; annulus simple, narrow, persistent. — Spec. Muse. 270, 

 t. 70. II. viride, Lam. ; Lindb. Muse. Scand. 35. Brachythe- 

 cium pojmlexim, Bruch & Schimp. Bryol. Eur. t. 535, 536. B. 

 plumosum, var. reflexuni., Austin. 



Var. majus. More robust and densely foliate : leaves 

 longer. — Bruch & Schimp. 1. c, as Brachythecium. 



Var. longiseturQ. Larger and more rigid : leaves erect or 

 subsecund : caj^sule long-jjedicellate. — Bruch & Schimp. 1. c. 



Var. subfalcatum. Slender; branches incurved: leaves 

 subfalcate, soft, glossy. — Bruch & Schimp. 1. c. 



Hab. Plains and mountains of the Atlantic States; mostly on granite 

 boulders. 



58. H. plumosum, Swartz. Moncecious: plants more 

 robust than in the last ; tufts short, dense, yellowish or dirty 

 green ; stems hard, densely ramose ; branches mostly simple, 

 erect or arcuate, densely foliate, pinnately ramulose : leaves 

 open or homomallous, broadly ovate or deltoid-ovate, short, 

 obliquely acuminate, entire, solid, shining, costate to the mid- 

 dle : capsule slightly longer than in the last, but of the same 

 form, light brown, black when old ; pedicel smooth below ; 

 peristome perfect ; cilia two, as long as the segments, appendicu- 

 late ; annulus simple and persistent. — Muse. Suec. 66. H. 

 pseuclo-plumosum., Brid. Muse. Recent, ii. 2. 108 ; Muell. Syn. 

 ii. 350 ; Lindb. 1. c. H. chrysostomiim^ Michx. Fl. Bor.-Am. 



