HOW TO KNOW SOME OF THE COMMONER BRYUMS. 

 By Elizabeth G. Britton. 



THERE are about 500 species of Bryum ; 195 have been re- 

 ported from Europe and North America, 50 of which are 

 common to both. Taking it for granted that those who 

 will use this article know the differences between Leptobryum, 

 Webera, and Bryum, and that they are not likely at first to col- 

 lect any of the rarer species of the other sections, I will describe, 

 as briefly as possible, the few species of Eubryum and Rhodo- 

 bryum which are most often collected. Dividing the Eubryums, 

 as Dixon does, into two series, the first to include the larger spe- 

 cies with long, narrow leaves, excurrent costa, usually prolonged 

 into an awn, with tall pedicels, and capsules generally one-eighth 

 to one-quarter of an inch long; the second to include the smaller 

 species, with small leaves, rarely acuminate, the costa ending 

 with or below the apex; the capsules small, and often deep red. 

 In the first group we have five of the species described, four of 

 them common. 



Bryum bimum is common in wet woods at base of trees, in 

 swamps, on rocks and moist banks, and even on old stone walls 

 and railroad cuttings, having been reported from Newfoundland 

 to Vancouver Island, and in the United States from Maine to 

 Florida, and Washington to California. As Dixon says: "It is 

 not to be confounded with any other except B. pseiidotriquetrum, 

 on account of its robust habit, the large leaves with short points 

 and long capsules on a tall seta, and the synoicous inflorescence." 

 The stems are matted together by a red-brown felt of radicles, 

 and the leaves are twisted when dry, the margins strongly re- 

 curved, and bordered by several rows of narrow cells. The var. 

 elatum grows in very wet places, and I have collected it in a 

 spring in Smuggler's Notch, five inches high. Bryum pseudotri- 

 quetrum {B. ventricosum) is considered by Dixon to be only a 

 dioicous form of B. bttnum. It has the same range in the United 

 States, and often grows with it, here as well as in England. B. 

 intermedium is almost as common a species, with as wide a range, 

 preferring moist places, but resembling more in its leaves B. 

 ccESpilicium, from which it differs in being synoicous and in 

 maturing its capsules later, in summer and autumn, instead of 

 spring, having an incurved capsule with small mouth, and pale 

 teeth. 



