THE POLYTRICHACE.E OF WESTERN NORTH AMERICA 295 



indistinct; Peristome present; teeth 32 (in the included species), in 

 P. alpinum doubled so one might count 64. Lid hemispheric, more 

 or less long-beaked. Pedicels single, rarely several at one tip, more 

 or less elongated, purple. 



Number of species in western North America, 4; total number spe- 

 cies, about 133. 



THE WEST NORTH AMERICAN SPECIES, A COMPARISON AND KEY. 



i. Leaves very much crisped when dry. 

 2. Marginal cells of lamellae smooth, not thickened. 

 3. Teeth 32. 



4. Capsule without stomates. 

 5. Capsule papillose. 



6. Marginal cells of lamellae differing little in size and form 

 from the others i. P. contortum. 



i. Leaves hardly or not at all crisped when dry. 

 2. Marginal cells of lamellae papillose or rough, thickened. 

 3. Teeth 64, or 32 double ones. 

 4. Capsule with stomates. ' 

 5. Capsule not papillose. 



6. Marginal cells of lamellae ovate, width to length as i : 

 J-2, larger than the others 4. P. alpinum. 



3. Teeth 32. 



4. Capsule without stomates. 

 5. Capsule papillose. 



6. Marginal cells of lamellae oval or flat- topped, width to 

 length as 1^-2:1, larger than the others. 



2. P. capillare. 



6. Marginal cells of lamellae round, about the same size as 

 the others j. P. urnigerum. 



1, Pogonatum contortum (Menz.) Lesq., in Mem. Calif. Acad. i, 



p. 27. 



Pogonatum erythrodontium Kindb., in Mac. Cat. p. 150 (1892). 

 Pogonatum atrovirens Mitt., 14 in Journ. Linn. Soc. 1864, p. 49. 



14 An examination of P. atrovirens Mitt, shows it to be P. contortum. Type material 

 from the Mitten Herbarium, now owned by the New York Botanical Garden, and also 

 material collected by Macoun at Hastings, Burrard Inlet, near Vancouver, British 

 Columbia, was compared with authentic P. contortum. The capsules are papillose 

 as in P. contortum. The basilar areolation is the same in leaves taken from correspond- 

 ing parts of the stem. The leaves in both vary in the size of the sheath, those near 

 the base of the stem having larger sheaths than those near the tip. Since these con- 

 stitute the characteristics upon which P. atrovirens Mitt, is founded, it reduces to 

 P. contortum. 



