78 LESKEACEAE 



It is distinguished from Leskea by the much shorter costa, which 

 may be single and reach the middle of the leaf, or be shorter and 

 double, or even almost wanting: leaves much narrowed at base, 

 often obovate, very concave; inner peristome of 16 rather short 

 linear to irregular segments, without basal membranes or cilia. 



P. filiforme (Timm.) Hedw. "On rocks and roots of trees, 

 Palisades, N. J.," Muse. App. 280. 



ANOMODON Hook & Taylor. (Plate IX, Fig. 1.) 



Much like Leskea in habit of growth but much larger and 

 coarser (excl. A. rostratus and A. tristis), when fully developed 

 growing in mats consisting of a network of nearly leafless pri- 

 mary stems growing close to the substratum and sending up 

 secondary stems and branches in great numbers. The leaves 

 described are those of the secondary stems and branches, those 

 of the primary stems are usually quite different. The stems 

 lack paraphyllia. The leaves are densely papillose on both 

 sides and almost opaque, and have a single long, strong, pellucid 

 costa (shorter in tristis); leaf cells irregularly hexagonal, a few 

 in the median basal area usually elongated and pellucid. Cap- 

 sules and peristome much as in Leskea but the former borne on 

 the branches, the latter very brittle; inner peristome as a rule 

 less developed than in Leskea. All our species are dioicous. 



Key 



I — Secondary stems and branches slender, usually julaceous when dry. . 2 



Secondary stems and branches coarse, scarcely julaceous 3 



2 — Leaves slenderly acuminate, ending in a hair point; plants growing in 



moist places at base of trees and about ledges rostratus 



Leaves narrowly Ungulate from an ovate base, obtuse to apiculate; 



plants growing on bark of trees as a rule tristis 



3 — Secondary stems much branched as a rule, many branches attenuate 

 to flagellif orm ; some of the leaves apiculate and toothed at the 



apex attenuatus 



Secondary stems more sparingly branched, no attenuate branches. ... 4 

 4 — Upper portion of leaves Ungulate-lanceolate, conspicuously taper- 

 ing to the apex, somewhat contorted and crisped when dry, often 



secund : plants usually growing on rocks viticidosus 



Upper portion of leaves Ungulate and of nearly equal breadth, not 

 secund; plants nearly always growing on bark of trees, stumps or 

 logs 5 



