274 
W 
A sae ae 
If. 
II. 
FRYE 
KEY TO THE WEST NORTH AMERICAN GENERA. 
Lamelle on upper side of leaf 18 or fewer............-.e0-- 2. 
Lamellz on upper side of leaf 20 or more. .........26.meeee 8. 
eaves bordered <i: 3 sek ome ice ee Catharinea, p. 
Leaves not bordered... 5) 5:02. 4 melee eee ee 3; 
Leaf margin with long hairs where sheath grades into blade; 
lamina of two layers of cells; peristome wanting. 
Bartramiopsis, p. 
Leaf margin without hairs; lamina of 1 layer of cells; peristome 
PRCSOIN 2 ieee ses Riaia se Galo eye tis Ge Sem s e 4. 
Capsulemdisiinctly jcemmuouse, ae eee Psilopilum, p. 
Capsule straight or very nearly so........ Oligotrichum, p. 
Capsule wanting (for sterile specimens)/)2 1-7-2. 1s eee ce 
Lamelle straight; plant much crisped when dry. 
Oligotrichum parallelum, p. 
Lamellz wavy from side to side; plants not or very little crisped 
UCTS CLIN che. ec, aie Nae oat ak a Ale ree ee 6. 
Lamellz on back conspicuous, about equal in number and size 
to those on the upper side; leaf margin plane or erect. 
Oligotrichum aligerum, p. 
Lamellz on back inconspicuous or none; leaf margin incurved.7. 
Leaf margin abruptly incurved above the sheath; lamellz on 
back inconspicuous or none. . Oligotrichum incurvum, p. 
Leaf margin gradually incurved from base; lamelle on back 
Rea CMs eae | i, eae i a ane Psilopilum, p. 
Capsules 4-6 angled; teeth 64; calyptra densely hairy. 
Polytrichum, p. 
Capsules 2-4 angled; two of the angles nearer together than the 
others; teeth 64, calyptra with few hairs. 
Polytrichadelphus, p. 
Capsules terete; teeth 32,or 64 in Pogonatum alpinum; calyptra 
densely ary: seis, eek. eee te Pogonatum, p. 
Capsules wanting (for sterile specimens).................-- Q. 
Leaf margin entire, inflexed over the lamellz in most species. 
Polytrichum, p. 
earimarcim serrate. ¢ wc 2.. 2,60 eye eee ae ha ae 10. 
. Leaves verymuch crisped when dry. 
Pogonatum contortum, p. 
. Leaves little or not:at all crisped whenidins oye ee 1 
Marginal cells of lamella smooth or merely grooved. 
Polytrichum, p. 
Marginal cells of lamelle rough or papillose............... £2 
275 
289 
288 
281 
282 
284 
285 
298 
304 
291 
294 
304 
295 
304 
