282 FRYE 



THE WEST NORTH AMERICAN SPECIES, A COMPARISON AND KEY. 



i. Lamellae straight; capsule with few stomates. 

 2. Leaf margin plane. 

 3. Lamellae on upper side 4-7 ; 3-6 cells high. 



4. Lamellae on back low or wanting i. O. parallelum. 



i. Lamellae wavy from side to side; capsule with numerous stomates. 

 2. Leaf margin plane. 

 3. Lamellae on upper side 5-7 ; 3-7 cells high. 



4. Lamellae on back high 2. O. aligerum. 



2. Leaf margin incurved. 

 3. Lamellae on upper side 10-13; 6-12 cells high. 



4. Lamellae on back low or wanting 3-O. incurvum. 



1. Oligotrichum parallelum (Mitt.) Kindb., in Eur. and N. Amer. 



Bryin., p. 156, (1897). 



Atrichum parallelum Mitt., in Journ. of Linn. Soc., 1864, p. 48, t. 8. 

 Atrichum leiophyllum* Kindb., in Bull. Torr. Bot. Club. 17: 275, 



(1890). 

 Oligotrichum leiophyllum Kindb., in Eur. and N. Amer. Bryin., 



p. 156 (1897). 



Probably so named because there are often tooth-like processes 

 parallel to the vein on the backs of the leaves. 



Plants dioicous, loosely caespitose, dark green; antheridial plants 

 more slender, the antheridial disks cupshaped. Stems simple, 

 erect, 13 cm. tall. 



Upper leaves half open, incurved when moist, slightly undulate, 

 ligulate-lanceolate, often marked on the back by small thin tooth- 

 like processes parallel to the vein; lower leaves shorter, oblong, more 

 obtuse. Margin plane, sharply dentate from the middle or below. 

 Lamellae on upper side 4 7, straight. Vein percurrent, sometimes 

 with 13 longitudinal dentate lamellae on back. Cells round- 

 hexagonal, basal cells narrow. Perichaetial leaves oblong, convolute 

 at base, gradually narrowed, lanceolate. 



Capsule as 1:3 4, subcylindric, slightly arcuate, contracted 

 under the mouth, with few stomates. On soil. Kodiak Island, 

 Port Etches, and Douglas Island, Alaska; Vancouver Island, and 

 Rocky Mountain region of British Columbia; Washington. 



4 See Proc. Wash. Acad. Sci., 4: 326, (1902). 



