92 A MANUAL OF MOSSES 



McKean : Bradford, November 21,1896, Divide, Bolivar 

 and Bennett, December 15, 1896, and Quin- 

 tuple, March 20, 1898. D. A. B. 



Washington: Linn and Simonton. (Porter's Catalogue). 



3. GYMNOSTOMUM Hedwig. 



Dioicous: densely cespitose, rusty in color below: stem 

 thickly foliate, sparsely radiculose, in cross-section circular, 

 the central strand few-celled, the branching dichotomous; 

 leaves erect-spreading, more or less carinate, not crisped when 

 dry, rarely appressed or curved ; elongate-lanceolate or subu- 

 late, margin plane; costa strong, vanishing below the apex; 

 upper leaf-cells rounded-quadrate, small, thickly papillose on 

 both sides, as is also the costa, lower cells rectangular, the 

 walls yellow; perichsetial leaves somewhat sheathing at the base; 

 seta long, erect ; capsule erect, symmetric, oval or oblong, when 

 ripe smooth and shining, the wall of the capsule not distinctly 

 thickened at the mouth ; peristome none ; operculum conic, 

 rostrate, easily deciduous; calyptra narrowly cucullate, cover- 

 ing about half of the urn. 



A widely distributed genus of 11 species, mainly occurring 

 on calcareous rocks ; 3 species occurring in North America ; 

 only one in our region. 



1. Gymnostomum calcareum Nees and Hornschuch. 

 (Plate XII) 



Densely cespitose, yellowish-gteen : stems erect, 

 branched, up to 10 mm. high or more; leaves about I mm. 

 long, spreading, somewhat fecurved, elDngate-oblong-lanceo- 

 late, somewhat concave, usually larger and tufted at the apex 

 of the stem, obtuse, plane-margined ; upper leaf-cells densely 

 papillose, small, incrassate, obscure, the interior basal cells 

 hyaline, rectanglilaf or up to 2-3 :1 ; costa strong, ending be- 

 low the apex : seta erect ; capsule oblong, often somewhat con- 

 stricted below the mouth when dry and empty, erect, sym- 

 metric, tapering below ; lid conic, obliquely rostrate, the beak 

 one-half to two-thirds as long as the urh ; calyptra cucullate ; 

 peristome none; exothecial cells Rectangular to quadrate, at 

 the mouth becoming smaller, dkrker and quadrate in 3 to 5 

 rows; spores smooth, .008-.011 mm. in diameter, mature in 

 summer. 



Cosmopolitan on damp limestone rocks and boulders, 

 but rare in our region. 



Lawrence : Gorge near Rock Point, June 26, 1909. (Fig- 

 ured.) Sterile. O. E. J. 



4. HYMBNOSTYLWM Bridel. 



Dioicous : densely and deeply cespitose, green to rusty or 

 yellowish-green : stem densely foliate, sparsely radiculose, 



