282 FRYE 
THE WEST NORTH AMERICAN SPECIES,—-A COMPARISON AND KEY. 
1. Lamelle straight; capsule with few stomates. 
2. Leaf margin plane. 
3. Lamelle on upper side 4-7; 3-6 cells high. 
4. Lamelle on back low or wanting.......... 1. O. parallelum. 
1. Lamelle wavy from side to side; capsule with numerous stomates. 
2. Leaf margin plane. 
3. Lamellze on upper side 5-7; 3-7 cells high. 
ao Lamelle on back high... 2.---. ee eee 2. O. aligerum. 
2. Leaf margin incurved. 
3. Lamelle on upper side 10-13; 6-12 cells high. 
4. Lamelle on back low or wanting.........:... 3. O. incurvum. 
1. Oligotrichum parallelum (Mitt.) Kindb., in Eur. and N. Amer. 
Bryin., p. b56,.( 1807) 
Atrichum parallelum Mitt., in Journ. of Linn. Soc., 1864, p. 48, t. 8. 
Aitrichum leiophyllum* Kindb., in Bull. Torr. Bot. Club. 17: 275, 
(1890). 
Oligotrichum letophyllum Kindb., in Eur. and N. Amer. Bryin., 
DEON oO7 ): 
Probably so named because there are often tooth-like processes 
parallel to the vein on the backs of the leaves. 
Plants dioicous, loosely cespitose, dark green; antheridial plants 
more slender, the antheridial disks cupshaped. Stems simple, 
erect, 1—3 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. 
Lamellez on upper side 4—7, straight. Vein percurrent, sometimes 
with 1—3 longitudinal dentate lamella on back. Cells round- 
hexagonal, basal cells narrow. Perichetial 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. 
4See Proc. Wash. Acad. Sci., 4: 326, (1902). 
