THE POLYTRICHACEZ OF WESTERN NORTH AMERICA 275 
12. Plants erect; marginal cells of lamelle not higher than wide, 
CXCE DU Mtl i) UU ieee en ae ee ee Pogonatum, p. 294 
12. Plants decumbent; marginal cells higher than wide. - 
Polytrichadelphus, p. 291 
CATHARINEA Ebhrh. 
Atrichum Beauv. 
Named after the Empress Catharine IT of Russia. 
Plants not very tall. Stems with abundant rhizoids at base. 
Leaves without sheath, more or less transversely undulate, gener- 
ally with diagonal rows of teeth on the back, mostly crisped when 
dry. Margin plane, bordered except in young leaves, singly or 
doubly serrate with coarse sharp teeth. Lamellz 1-10, restricted 
to the vein, composed of similar smooth cells, margin entire. Vein 
3 the leaf-width or less, percurrent or vanishing, without lamelle on 
the back, often toothed on back near apex. Cells all smooth, chloro- 
phyllose, mostly quadratic, upper ones hexagonal or elliptic-hexa- 
gonal. 
Calyptra naked, or with a few hairs or teeth at the tip. 
Capsule somewhat inclined, curved, never angular, smooth, with- 
out stomates. Peristome present; teeth 32, pale, with yellow or 
brown middle line. Lid long-beaked. Pedicel smooth, solitary or 
sometimes 1-3 from a stem-tip. 
Number species in western North America, 4; total number 
species, about 33. 
THE WEST NORTH AMERICAN SPECIES,—A COMPARISON AND KEY. 
1. Capsule as 1:4; leaves not wavy along the margin when moist. 
2. Vein constituting $—,', of the leaf-width. 
3. Lamelle 1-2 cells high. 
Ae Cells) 625.045. mim: 
Fae wamina wabnout teetmanoacko.).). 0.0.15 .n68 Ta. Cres pe. 
1. Capsule as 1: 6-8; leaves slightly to distinctly wavy along mar- 
gins when moist. 
2. Vein constituting 4-4 of the leaf-width. 
-3. Lamelle 5-8 cells high. 
4. Cells .o10—.020 mm. 
5. Lamina mostly with teethat back........ 2. C.angustata. 
2. Vein constituting 4-74 of leaf-width. 
3. Lamelle 3--5 cells high. 
