Jennings: Manual of Mosses — 18. Bartramiaceae 149 



stem with central strand usually distinct, erect, monopodial or dichotomous, 

 branches not whorled; leaves mostly 8-striate, from a mostly half-sheathing 

 base gradually or abruptly subulate-linear, serrate upwards and often on the 

 back of the costa; lamina upwards, sometimes only at the margin, two-layered; 

 costa strong, projecting dorsally, incomplete to excurrent; leaf-cells small, in- 

 crassate, rectangular, mamillate on both sides, the basal elongate rectangular 

 to linear, smooth, pellucid to hyah'ne: seta mostly 1-2 cm long, rarely very 

 short, mostly straight; capsule mostly inclined, somewhat arcuate, with mouth 

 oblique, globose, no collum, when dry mostly sulcate, more or less shrunken 

 in the middle and flattened on the ends; peristome double or single, rarely 

 none, teeth not united at the apex, neither with inter-!amel!ar thickenings; cilia 

 mostly none; lid small, inflated to short-conic. 



A cosmopolitan genus of more than 100 species, on earth or rocks in dry 

 or moderately moist habitats; at least 15 species in North America; two 

 species in our range. 



Key to the Species 



A. Leaf-base neither sheathing nor conspicuously scarious, margin revolute 



1. B. pomiformis 



A. Leaf-base scarious and sheathing, margin plane 2. B. ithypbylla 



1. Bartramia pomiformis Linnaeus, p.p., Hedwig 

 Apple Moss 



Plate XXVIII 



Rather densely cespitose, soft, yellowish-green: stems about 1.5-3 cm long, 

 erect, densely reddish-brown-felted below; leaves about 4-6 mm long, the lance- 

 subulate part spreading rather abruptly from a more or less erect and concave 

 but scarcely sheathing lance-ovate base, more or less crisped when dry. the 

 margin revolute in the basal half at least, serrate above, the costa rather nar- 

 row and distinct, e.xcurrent in a spinulose-serrate subulation; basal leaf-cells 

 smooth, hyaline, often reddish-brown and pellucid at insertion, elongate-rectan- 

 gular, the marginal shorter in a few rows, median cells rounded-quadrate, 

 incrassate, papillose: seta about 5-10 mm long, erect or curved-ascending, 

 smooth, reddish-brown; capsule globose, about 1.5 mm in diameter, striate, 

 unsymmetric, reddish-brown when ripe, globose to oblong or narrowly oblong, 

 when dry deeply sulcate, cernuous, occasionally strumose, often somewhat 

 arcuate; peristome double, teeth reddish-brown, narrowly triangular-lanceolate, 

 faintly papillose, prominently articulate, sub-trabeculate, divisural faint, zigzag; 

 segments two-thirds as long as teeth, carinately split, the cilia two or three and 

 rudimentary, or none; lid convex, bluntly umbonate; calyptra narrowly cucul- 

 late, about 2 mm, long; spores reddish-brown, pellucid, coarsely papillose, 

 mature in May or June. 



Cosmopolitan on rocks or swampy soil in moist and shady woods; in 

 North America from the Arctic regions to Florida and Colorado. 



This is an easily recognized moss. The leaves look like tufts of green 

 wool and are surmounted by slender stemmed fruits like miniature apples. 



Common in our region — known from 15 counties in western Pennsylvania and prob- 

 ably occurs in all. Speimen figured: On clay roadside ban'<, Hartstown. Crawford Co., 

 May 29-31, 1909. O.E.J. & G.K.J. 



