178 
Bor. Am. (Ed. 1) 331, (Ed. 2) 494 and 495 ; Austin, Musc. Appal. 
318; Ren. & Card. Musc. Am. Sept. Exsic. 243. 
Quite variable in size and shape of leaves and in gross appear- 
ance. Macoun’s Can. Musc. 591 on which P. leucoglaucum C. 
Muell & Kindb. was founded has the seta very rough and cannot 
be distinguished from this species. 
10a. BRACHYTHECIUM RUTABULUM FLAVESCENS (Brid.) Br. and Sch. 
Bryol. Eur. fasc. 52-54. A. 544. 
Hypnum flavescens Brid. Spec. Musc. h. f. 185. 1812. 
Lrachythecium platycladum C. Muell. & Kindb. Macoun, Cat. 
tan PLO: 195... 1892. Can. Musc. 287, in part. 
Plants straw-colored, very stout; stem and branches loosely 
foliate, turgid ; stem leaves very broadly ovate, concave, abruptly 
short-acuminate. With the typical form. Montana (R. S. Will- 
iams) ; Jamaica Plains, Mass. (E. Faxon). 
At first sight this form seems distinct from B. rutabulum but 
there is a complete gradation of forms from the typical plant to the 
variety. The stem leaves often resemble those of P. rivulare but 
they are longer acuminate and some of the branch leaves are not 
much different from those of typical P. rutabulum. 
This variety seems imperfectly dioicous, as both Kindberg and 
R. S. Williams describe it as dioicous. The Columbia specimen of 
Macoun's 287 (which is undoubtedly the same as that described 
by Kindberg) contained plants which bore both male and female 
branches. 
II. BRACHYTHECIUM ASPERRIMUM Mitt. Journ. Linn. Soc. 8: 33. 
1865. 
Hypnum vallium Sull. & Lesq. Musc. Bor. Am. Ed. 2, 506. 
1865. : 
Brachythecium Villardi R. & C. Bot. Centralbl. 44 : 442. 1890. 
Brachythecium gemmascens C. Muell. & Kindb. Macoun, Cat. 
Can. Pl. 195. 1892. 
Brachythecium spurto-rutabulum C. M. & Kindb. 1. c. 197. 
Brachythecium Columbico-rutabulum Kindb. |. c. 198. 
Brachythecium subintricatum Kindb. Rev. Bryol. 22: 86. 1895. 
Gametophyte in wide loose mats, yellow-green; stems 5—r1 
cm. long, decumbent or ascending and arcuate, stoloniferous at the 
