Jennings: Manual of Mosses — 18. Bartramiaceae 147 



entire; upper cells mostly rectangular, thick-walled, the lower elongate and 

 hyaline: seta usually very long, inner peristome with a very low basal mem- 

 brane; segments 2 to 4 times the length of the teeth, often more or less united 

 at the tip; cilia short or rudimentary, often being represented by a chain-like 

 series of thickenings on the persisting wall of the inner peristome. 



Ten species in bogs and wet places; four species in North America; two 

 species may be looked for in bogs and swamps in the northern part of our 

 region. 



Key to the Species 



A. Leaves three-ranked, serrate; dioicous 1. M. triquetra 



A. Leaves 5-8-ranked, entire; synoicous (M. longiseta Hedwig)* 



1. Meesia triquetra [Linnaeus] Aongstroem 

 (M. tristicha (Funck) Bryologia Europaea) 



Loosely cespitose, dark green: stems elongate, radiculose below, sparingly 

 branching; leaves three-ranked, distant, lanceolate to ovate-lanceolate, acute, 

 strongly iquarrose from a concave strongly decurrent half-clasping base, the 

 spreading portion carinate, the margins sharply serrate; costa strong, ending in 

 the apex or just below; upper leaf-cells rectangular to hexagonal, incrassate, 

 the lower hyaline, elongate-rectangular; perichaetial leaves larger, about six in 

 number: seta long; capsule pyriform, curved from a long erect collum, when 

 dry and empty more or less wrinkled and twisted; peristome-teeth 16, short, 

 unequal, bifid; segments alternate, 16, about three times as long as teeth, united 

 below into a low basal membrane, yellowish, linear, irregularly articulate and 

 appendiculate; exothecial cells at mouth very small and in several rows, darker; 

 lid convex-conic; spores large, ripening in summer. 



In bogs and swampy woods, Europe, Asia, and, in North America, from 

 New Jersey, eastern Pennsylvania, Ohio and Lake Superior, north and west 

 to Arctic America and the Pacific Ocean. 



Family 18. Bartramiaceae 



Dioicous or synoicous, rarely paroicous or autoicous: slender to very 

 robust, cespitose: stems with central strand, erect, dichotomous or more often 

 with whorled "sub-floral" innovations, leaves 5-8-seriate, little or not at all 

 decurrent, lance-ovate to lance-subulate, non-bordered, serrate marginally above 

 and often also on the back of the costa; costa mostly strong, with median 

 guides, ending below or in the apex or excurrent in a serrate arista; cells paren- 

 chymatous, round-quadrate to elongate-rectangular, rarely linear, mostly thick- 

 walled, mostly mamillate on both sides; basal cells either not wider, or lax, 

 wider, and hyaline, mostly smooth, alar cells rarely differentiated: seta usually 

 long and straight, little or not at all twisted when dry; capsule erect to cernu- 

 ous, rarely pendent, more or less globose, darkly striate, collum rarely distinct, 

 mouth oblique or rarely symmetrical, exothecial cells rectangular to hexagonal, 

 several series at the mouth laterally elongate; annulus none or very incomplete; 

 peristome mostly double or sometimes single or rudimentary, or lacking alto- 



* In swamps and sphagnum bogs as far south as New York and Ohio. 



