3 20 



FRYE 



Named after Jensen. 28 



Plants lighter in color than P. commune. Stem 3-5 cm. high. 



Leaves about 8 mm. long, somewhat spreading when moist, but 

 erect when dry, sheath to blade about as i : 2 ; apex blunter than in 

 P. commune, dentate; a brown spot where sheath joins blade near 

 vein. Margin plane below, erect or slightly incurved above, en- 

 tire below, somewhat serrate in the upper half. Lamellae 30-35, 

 6-8 cells high; marginal cells notched in cross section, smooth, 

 thickened. 



Capsule 4-angled, width to length about as i : ii, smooth, porose. 

 Teeth 64. Lid conic, with a short slightly crooked beak. 29 In 

 Sphagnum bogs and on soil. Nome, Alaska; Yellowstone National 

 Park, Wyoming; Greenland; northern Europe. 



Fig. 25. Polytrichum yukonense. 



1 = Plant, X i. 2 and 3 = Leaves, showing lamellae on upper side, X 13. 4 = 

 Cross section of leaf, X 34. 5 = Cross section of a lamella, showing notched marginal 

 cell, X 135. 6 = Portion of a lamella as seen from side showing irregularity of cell 

 form and arrangement, X 270. (After Cardot & ThSriot.) 



38 C. O. E. Jensen is a Danish apothecary at Kirke Hvalsd, Denmark. 



29 This is not a description of the plant, but a noting of some of the characters from 

 specimens and verification of points from Asa Gray Bulletin and from Bryologist, 

 4; p. 26. Literature containing Hagen's description was inaccessible to the writer. 



