Jennings: Manual of Mosses — 12. Funariaceae 117 



2. Physcomitrium (Bridel) Fuernrohr 



Autoicous: mostly minute, densely gregarious to cespitose, green, mud- 

 inhabiting mosses: stem erect, simple, radiculose below, loosely foliate; leaves 

 flaccid, mostly appressed when dry, spreading when moist, concave, obovate to 

 oblanceolate or spatulate, mostly not margined, more or less serrate, obtuse 

 to acuminate; costa mostly strong, incomplete to excurrent; areolations lax: 

 seta mostly long; capsule erect, symmetric, globose to short-pyriform, with lax 

 areolation; collum short and thick; annulus small-celled and persistent or large- 

 celled and disappearmg in pieces; gymnostomous; spores large, papillose; oper- 

 culum broad, conic-onvex, umbonate or apiculate; calyptra long and erect- 

 rostrate, mitrate, lobed to the base of the beak, covering one-half or less of the 

 capsule. 



A cosmopolitan genus of about 75 species; about 20 species in North 

 America, at least 2 sF>ecies in our range. 



Key to the Species 



A. Seta very short; capsule immersed, wide-mouthed; calyptra small .1. P. immersum 



A. Seta longer; capsule exserted, not wide-mouthed; calyptra larger 2. P. tuTbtnatum 



1. Physcomitrium immersum Sullivant 



(Gymnostomiim immersum Sullivant) 

 Plate XX 



Plants small, erect, gregarious, light green, simple or branching, 3-8 mm 

 high; leaves 1.5-3.5 mm long, obovate to oblanceolate, serrate above the mid- 

 dle, spreading to ascending; costa strong, ending a little below the apex; 

 leaf-cells parenchymatous, rather large and thin-walled, the basal rectangular, 

 about 2-5:1, the upper irregularly oblong, the marginal narrower and in the 

 alar region a few much shorter: capsule immersed, globose to pyriform-globose, 

 0.6-0.9 mm in diameter, apiculate-rostrate, about the upper two-fifths consti- 

 tuting the operculum, yellow-brown when ripe; seta considerably shorter than 

 capsule and stout; exothecial cells irregularly quadrate to hexagonal, somewhat 

 mcrassate, the annulus consisting of one to three rows of much smaller, orange- 

 pellucid, to brown-pellucid cells, the cells of the wall usually laterally elon- 

 gated for one or two rows above and below the annulus; calyptra mitrate, the 

 basal margin 4-5-lobed, covering about one-half of the operculum; spores d nse- 

 ly papillose, orange to brownish-pellucid, globose, in our specimens about .035 

 mm in diameter, mature in autumn. 



Usually on clayey or sandy flood-plains where submerged in time of 

 freshets. Quebec to Colorado, Missouri, r.nd the Carolinas, but not commonly 

 collected, probably on account of its small size and special habitat. 



Allegheny Co.: Bare clay bank of creek, Darlington Hollow, Aspinwall. Oct. 25, 

 1908. O.E.J. ; Mud cracks m dry pond basin, Glenshaw. Oct. 30, 1932. J. L. Cart- 

 ledge. Beaver Co.: Clay bank of Little Beaver Creek, New Galilee, Sept. 10, 1906. 

 O.E.J.; Bank of Ohio River, Smith's Ferry, Oct. 1, 1910. O.E.J, (figured). Butler 

 Co.: On ground in cornfield, Millinger School, Dec. 2, 1934. Sidney K. Eastwood. 

 McKean Co.: East Branch, Bradford. June 15. 1895. D.A.B. 



