Jennings: Manual of Mosses — 31. Hypnaceae 233 



3. Hygroamblystegium orthocladon (P.B.) Grout 



(Hypnum orthocladon P. Beauvois; Amblystegium orthocladon (P.B.) Jaeger) 



Plates XLI, LXVI 



This plant is regarded by Grout after extensive study as belonging to 

 Hygroamblystegium, intermediate between H. irrtgutim and the wider and 

 more obtuse-leaved variety brevifolium of H. fluviatde. In deference to Dr. 

 Grout's extensive studies in this group I am here placing it under Hygro- 

 amblystegium. 



Rather dark green, sometimes olive-green, rather stiff when dry, commonly 

 tufted; stems irregularly branched, the branches of plants in the denser tufts 

 often erect and sometimes 2 cm tall, but usually less than 1.5 cm long; leaves 

 up to 1 mm long, broadly cordate-ovate, usually rapidly and uniformly nar- 

 rowed to an acute or sub-obtuse apex, rounded to a narrower base, slightly 

 concave, slightly decurrent, widely spreading both wet and dry, the margins 

 plane and entire; branch-leaves smaller, narrower, and more acute; costa strong, 

 wide at base, yellowish, usually extending up into the apex; leaf-cells sub- 

 incrassate, the median oblong-rhomboidal to elongate-hexagonal, Vv'ith rounded 

 ends, .010-. 020 mm long, about 2-4 (-6) :1, the apical similar, th? mec'ian basal 

 oblong-rectangular, the cells of the angles somewhat wider, varying to short- 

 rectangular or quaorate, incrassate, often op::que or colored: seta ur.uaHy about 

 1-1.5 cm long but occasionally reaching 3-4 cm; castaneoas; capsule ca3taneous, 

 oblona-c/lindric, arcuate, cernuous, constricted below the rim -when diy, nar- 

 rowed at base to a distinct neck, the urn about 1.6-1.9 (to 3) mm long; peri- 

 stome typically hypnoid; basal membrane high, cilia about equalling seginents; 

 operculum short-conic; spores mature in spring, somewhat incrassate, smoothish, 

 about .010-018 mm. 



On stones, rotten wood, bases of trees, etc., along or in brook; or in moist 

 situations in woods; Europe, and probably widely ranging through more ele- 

 vated parts of eastern United States. Grout {Moss Flora') treats it as a sub- 

 species of Hygroamblystegium irriguum. The specimen figured from \Vash- 

 ington County is unusually large. 



Now known from the following countias: Allegheny, Butler, Crawford, Favette, 

 Greene, McKean, Warren, Washington, and Westmoreland. Specimens figured: Cheat 

 Haven, Fayette Co., Sept. 26, 1910. O.E.J, dc G.K.J. (Plate XLI).; On stonos in Calcar 

 Spring, Snake woods, near Washington, Washington Co., Dec. 12, 1897, A. Linn and 

 J. S. Simonton (Plate LXVI). 



4. Hygroamblystegium filicinu.m [Linnaeus'] Loeske* 



(Amblystegium filiciniirn DeNotaris; Stereodon filiciniif Mitten; Hypnum 

 compressum Bridel, Cratoiieuron flic'inum Roth) 



Variable, forming loose to dense tufts, rather rigid, bright or golden yel- 

 low: stems usually densely brownish tomcntose, especially en the prostrate or 

 procumbent forms, rather regularly pinnately branched, with usually numer- 

 ous oval to lanceolate, laciniate oaraphyllia; brarxhes slend:r, short, stiff, non- 

 tadiculose, with few or no paraphvllia, usually hooked at the ape."-:; stem-leaves 



* Grout {Moss Flora) treats this as a species of Critoncuron. 



