— 41 — 



study of this species. In this case the largest plants in my No. 83a of N. 

 Am. Musci Pleurocarpi should be labeled E. fallax var. Taylorae (R. S. 

 Williams). These plants with branch leaves fully the size of Mr. Williams' 

 type (1.5mm long) and other dimensions to correspond, grow inextricably 

 intertangled with forms of the ordinary size. Mr. Williams' statement that 

 "in size this plant most nearly approaches E. Oregamim of any of our 

 North American species," is a clue which will readily enable the collector to 

 recognize it. Mr. Williams type is Leiberg's No. 172 from the Traille River 

 Basin, Idaho. 



Brachyiheciiim Pringlei is most certainly a mere variety of B. plunio- 

 siim and differs from the var. homomalhtm only in its larger size and 

 broader and less slenderly acuminate leaves. Except for a slight difference 

 in these respects it agrees almost exactly with Edition I, No. 332b of the 

 Muse. Bor. Am. of Sullivant and Lesquereux. 



The only possible reason for giving this varietal rank ^B. plumosuin 

 var. Priiiglei S. W.)] lies in the fact that the European authors describe 

 the var. hoinomallum as more slender than the typical form and with smaller 

 leaves.. But on the other hand the American form of the species averages 

 considerably smaller than the European. My own opinion is that the plant 

 described by Mr. Williams should be regarded as a mere form of var. 

 homo77ialluin. Mr. Williams' type is from the Huachua Mts., Arizona, col- 

 lected by Mr. C. G. Pringle. 



In the Bulletin of tiie New York Botanical Garden, Vol. 2, No. 6, May 

 27, 1901, Mr. Williams describes Brachythechuii petj^ophilum from Dawson 

 as new. This moss belongs in the difficult and variable Collimim group 

 which is not well understood by any one as to its American forms. Mr. 

 Williams* plant is not just like any other known to me yet it is so near some 

 of the already too numerous species of this group that I think it unfortunate 

 that it should be given specific rank until the whole group is better under- 

 stood. If typical Brachyiheciiim erythrorrMzon var. Thedetiii, had ever 

 been found in that part of the world I should refer it to that variety, from 

 which it differs in its more crowded, less longly acuminate, less falcate 

 leaves: with which it agrees in general form and areolation of leaves and 

 slightly scabrous seta. 



Mr. Williams says that his plant is nearest to B . stiberythrorrhizon from 

 which it differs "in the rough pedicel, leaves narrower, less serrate and 

 plicate and cilia appendiculate," 



A close examination of a seta of the type of suberythrorrhizon shows 

 several low papillae. I was unable to make out the difference in the serra- 

 tion of the leaves; the amount of projection at the nodes of the cilia in 

 this group is notoriously variable. I do not think suberythrorrhizon is 

 as distinct from erythrorrhizon as is the var. Thedenii, but if it be held a 

 good species, then Mr. Williams' plant should be regarded as a poorly 

 marked variety. 



Thanks to the courtesy of Mrs. Britton and the New York Botanical 

 Gardens, I have had access to the types, which I have carefully studied. 



