Jennings: Manual of Mosses — 2. Dicranaceae 47 



Bruchia Sullivantii Austin 



Plate LX 



Very clojc to B. flexuosa, from which it differs mainly in having shorter 

 stems; the neck about as long as the spore-sac. Leaves suddenly canaliculate- 

 subulate from an ovate concave base, smooth or nearly so, basal cells thin- 

 walled, elongate rectangular, often very irregular, with an indistinct margin of 

 linear somewhat incrassate cells; cells at shoulder much shorter, polygonal, 

 thicker walled; costa strong percurrent: seta curved, 1-1.5 mm long; capsule 

 oblong-pyriform 1-2 mm long, acuminate, the neck about as long as the 

 spore-sac; calyptra about one-half the length of capsule, smooth; spores spinu- 

 lose, mature in June. 



On clay soil in fields from New England to Minnesota, south to the Gulf 

 States. Occurs in eastern Pennsylvania and in Ohio. 



Butler Co.: One mile north of Moniteau, Cherry Twp., on soil m old cornfield. Sid- 

 ney K. Eastwood. June 6, 1935 (figured). 



2. Trematodon Richard 



Autoicous, rarely dioicous; low, singly disposed: stem with a large central 

 strand and loose ground tissue; leaves yellowish-green, abruptly to gradually 

 lance-subulate from a broad clasping base, more or less crisped when dry; costa 

 ending below the apex or percurrent; cells thin-walled, loosely elongate-hexag- 

 onal to rectangular or, above, rhombic-pentagonal or -he.xagonal: seta yellow, 

 erect, rarely tortuous to cygneous; capsule with a long tapering neck, moder- 

 ately arcuate, the urn smooth, annulus differentiated; peristome-teeth united 

 below into a low basal tube, undivided and cribrose or two-parted to the base 

 into filiform divisions, articulate and longitudinally striate, peristome rarely 

 lacking; operculum as long as the urn, obliquely rostrate; calyptra inflated, 

 cucullate, not ciliate. 



A cosmopolitan genus of about 70 species, of which about 10 occur in 

 North America, 2 of these in our region. 



Key to the Species 



A. Collum as long as urn of capsule 1. T. ambiguus 



A. Collum twice as long as urn 2. T. longicollis 



Trematodon ambiguus (Hedwig) Hornschuch 



Plate LXXII 

 Gregarious, erect, simple or sparingly branched; stems 6-10 mm tall, 

 densely brownish radiculose below; leaves 4-8 mm long, from an ovate or ob- 

 long, concave, sheathing base abruptly narrowed to an equally long or some- 

 what longer linear-subulate, channelled apex, minutely serrulate at the tip; 

 costa at base thin, about one-fifth or one-sixth the width of the leaf, from 

 there percurrent and constituting most of the linear-subulate upf>er part of the 

 leaf; cells at base of leaf thin-walled, oblong-rectangular, somewhat inflated, 

 about .010-.02C mm wide by 2-5 times as long, at the margin a few rows much 

 narrower, the cells at the shoulder where the sheathing base suddenly tapers 



