Jennings: Manual of Mosses — 29. Leskeaceae 203 



ened, imbricate when dry, ovate, long and slenderly acuminate, strongly pap- 

 illose, entire; costa ending above the middle; leaf-cells unipapillate, elliptic- 

 rhomboid above, the basal marginal thick, rounded-quadrate; perichaetial 

 leaves longer, lance-acuminate: seta short, erect; capsule erect, oval-cylindric 

 with a small mouth; teeth broadly lanceolate, deeply inserted, opaque, papil- 

 lose on both surfaces, the inner peristome consisting merely of a low basal 

 membrane scarcely exceeding the rim of the urn; annulus none; lid short- 

 conic; spores mature in summer. 



On tree-trunks and on rocks or stone-walls; southern Canada to South 

 Carolina and Arizona. In Porter's Catalogue the habitat is given as juniperiis 

 virginianiis. Not yet collected in our region. 



6. Leskea Hedwig 



Autoicous: rather slender, usually weak, loosely cespitose, dull, dark to 

 sooty-green: stems creeping, sparsely radiculose, rather thickly-leaved, more or 

 less pinnately branched, with short, erect or ascending branches; leaves when 

 dry imbricate, when moist erect-spreading to spreading, sometimes sub-secund, 

 from a somewhat decurrent, cordate-ovate base narrowed to an acute or obtuse 

 apex, sometimes apiculate, shortly two-plicate, revolute on one or both lower 

 margins, rarely indistinctly serrate at apex; costa strong, incomplete; median 

 leaf-cells either thin-walled, rounded-hexagonal, one- to several-papillose, at the 

 base almost quadrate, in the middle rhomboidal, or more or less thickened, 

 with oval to oblong acumen; branch-leaves smaller; inner perichaetial leaves 

 pale, sheathing, abruptly to slenderly acuminate, entire or serrulate, at the 

 apex, delicately and incompletely costate: seta long, thin, red, smooth; capsule 

 erect, oblong-cylindric, sometimes slightly curved and weakly inclined, yellow- 

 ish, finally light brown and plicate; annulus revoluble; teeth drying strongly 

 incurved, linear, acuminate, entirely separate, non-bordered, pale yellow, at the 

 base transversely dorsally striate, thickly trabeculate, papillose above; inner 

 peristome papillose, basal membrane low, segments linear, carinate, as long or 

 shorter than the teeth, cilia rudimentary or none; lid acute-conic; calyptra 

 cucullate, glabrous; spores small. 



A widely distributed genus of about 15 species; 5 species reported for 

 North America; 2 (or 3) in our region. 



Key ro the Species 



A. Branch-leaves more or less secund, lanceolate; capsule sometimes slightly curved, 



usually straight 1. L. polycarpa* 



A. Branch-leaves not secund, ovate, acute to obtuse; cupsule erect, straight B 



B. Branch-leaves two-plicate, symmetric, the margin often revolute 2. L. gracilescens 



B. Branch-leaves non-plicate, often unsymmetric, plane-margined 3. L obscura 



* Leskea arenicola Best has pinnately branched stems with distinct, small, central 

 strand; stem-leaves lance-ovate to ovate and secund; branch-leaves smaller, but scarcely 

 secund; costa ending in the rather blunt acumination; capsule curved; segments as long as 

 teeth; basal membrane low: lid long-conical. 



Bases of trees, rotten wood, etc. New England to Virginia and west to the Mississippi. 

 Differ from polycarpa in more curved capsules and long conic opercukim. 



