344 A MANUAL OF MOSSES 



14. Brachythecium flagellare (Hedwig) New Combination. 



(Hypnum flagellare Hedwig; Hypnum plnmosum Swartz ; 

 B. plnmosum Bryologia Europsea). 



(Plate LII) 



Robust in loose, wide, green mats, brownish below : stems 

 prostrate, up to 5 or 6 or more cm. long, with rather densely 

 pinnate branches ; the branches stout, ascending to erect, some- 

 what tumid with the closely imbricate, concave leaves ; leaves 

 crowded, erect-spreading when moist, imbricated when dry, 

 often quite strongly falcate-secund, the branch-leaves lanceo- 

 late to broadly lance-ovate, abruptly slenderly acuminate, 

 about 1.3-2.0x0-4-0.9 mm., decurrent. serrate above to nearly 

 entire, the base very concave somewhat excavate at the al?e, 

 narrowed, sometimes striate when dry, margin plane or slight- 

 ly recurved at the base ; costa reaching to the middle or a 

 little farther; median leaf-cells narrow to linear, about 8-15:1, 

 the apical shorter, the basal shorter, the median basal en- 

 larged, rounded to oblong, incrassate, sometimes porose, the 

 alar somewhat smaller, oblong to sub-quadrate, in- 

 crassate and somewhat opaque ; stem-leaves similar, rather 

 scattered, usually smaller and narrower, about 1.5x0-6-0.7 

 mm., narrowly triangular-ovate; perichsetial bracts more or less 

 erect, partly sheathing : seta papillose in the upper half, cas- 

 taneous, stout, 1.5-2.0 cm. long, sinistrorse below, sometimes 

 dextrorse above; capsule about 1.5-2.5x1 mm., turgidly oval- 

 oblong, blackish when old, dorsally gibbous, horizontal to sub- 

 erect, somewhat unsymrnetric ; lid conic-acute about 0.6-0.8 

 mm. long ; annulus simple, persistent ; peristome-teeth cas- 

 taneous. confluent at base, strongly trabeculate and lamellate, 

 prominently margined by the projecting lamellae, dorsally 

 cross-striolate below, hyaline and papillose at apex ; segments 

 narrow, carinately split but usually not widely gaping, yellow- 

 ish, nearly as long as teeth, the basal membrane about one- 

 third as high ; cilia 2, nodose, hyaline, sometimes appendicu- 

 late below, about as long as the segments ; spores smooth, 

 medium-walled, brownish, about .013-.017 mm., mature in 

 autumn. 



On rocks in streams, in non-calcareous habitats ; Europe, 

 Asia, Hawaiian Islands, and from Newfoundland to British 

 Columbia and south in the mountains to Alabama. Very com- 



mon n our regon. 



Allegheny : Fourteen pockets, various localities, vari- 



ous data ; Wildwood Road Hollow, No- 

 vember 19, 1908. O. E. J. and G. K. J. 

 (Figured). 



Bedford : Along Wills Creek, near Hyndman, Octo- 



ber 9, 1904. O. E. J. 



