132 A MANUAL OF MOSSES 



1. Aphanorhegma serratum < I looker, f. and Wilson) Sulli- 



vant. 



(Plate XVI) 



Gregarious, light green: stems erect, simple or forking, 1- 

 5 mm. high, radiculose at base; leaves small and lance-oblong 

 below, rapidly becoming larger up to 3-5 mm. long, narrowly 

 lance-obovate above, the lower widely spreading and rlexuotis, 

 the inner erect-spreading, thin, slightly serrate above the 

 middle, apex acute to acuminate: costa medium, ending in or 

 just below the apex; the median basal cells thin-walled and 

 more or less inflated, rectangular, the marginal narrower, a 

 few quadrate at the base, becoming linear-rectangular above 

 the base, in the upper part of the leaf their tips extending as 

 low serrations, the median rhomboid to short rectangular 

 with walls medium, the apical longer and narrower: seta very 

 short and stout; capsule brown when ripe, globose to de- 

 pressed-globose, about 0.75 mm. in diameter, smooth to 

 apically papillose, splitting in the middle along a line of one 

 or two rows of small more or less orange-pellucid cells, the 

 upper half of the capsule ( operculum ) apiculate-rostrate ; 

 exothecial cells of capsule quadrate, conspicuously collenchy- 

 matous ; calyptra hyaline, conic-mitriform, 4-6-lobecl, covering 

 the upper half of the operculum ; spores globose, about .030 

 mm. in diameter, orange-pellucid or even darker, mature in 

 autumn. 



On damp clayey soil in the northern and middle United 

 States, in our region usually along streams where submerged 

 during periods of high water. 



.Allegheny : Stream banks. Fern Hollow, Pittsburgh, 



August 20, 1906; Guyasuta Hollow. No- 

 vember 9, 1908. and Thornhill, December 

 29, 1908. ( ). E. J. 



Fayette : Cheat Haven, September 6, 1910. O. E. 



j. and G. K. J. (Figured). 



2. PHYSCOMITR1TM ( B ridel ) Fuernrohr. 



Autoicous: mostly minute, densely gregarious to cespi- 

 tose, green, mud-inhabiting mosses: stem erect, simple, radicu- 

 lose below, loosely foliate: leaves flaccid, mostly appressed 

 when dry, spreading when moist, concave, obovate to oblanceo- 

 late or spatulate, mostly not margined, more or less serrate, 

 obtuse to acuminate: costa mostly strong, incomplete to ex- 

 current: areolation lax: seta mostly long; capsule erect, sym- 

 metric, globose to short-pyriforrn, with lax areolation; colluni 

 short and thick ; annul us small-celled and persistent or large- 

 celled and disappearing' in pieces; gymnostomous ; spores 

 large, papillose; operculum broad, conic-convex, umbonate'or 



