RYDBERG: Rocky MOUNTAIN FLORA 147 
Nuttall, however, did not publish it as Chrysopsis but as /nula, 
Chrysopsis being only a subgeneric name. The Kew Index cites 
DC. Prod. (4. c.) as the place of publication of the combination 
Chrysopsis alba, but it appeared at least one year earlier in Nees’s 
Genera. In describing the genus Uxamia, Dr. Greene stated : 
“And that the bristles of the pappus are visibly dilated at the tip 
is a character, here for the first time noted.”” This appears to be 
not quite the fact, for we find in the’sectional description in Torrey 
& Gray’s Flora: ‘the longer bristles clavellate-thickened at the 
apex ;” and in Gray’s Synoptical Flora: ‘‘pappus white, of rather 
rigid bristles, longer ones manifestly clavellate at tip.” The ex- 
pressions used by these authors are even more characteristic than 
Greene’s description, for the pappus-bristles are by no means flat- 
tened, as the word “dilated” usually implies. 
» Unamia lutescens (Lindl.) Rydb. comb. nov. 
Diplopappus albus 3 Hook. Fl. Bor.-Am 2: 21. 1834. 
Diplopappus lutescens Lindl.; DC. Prod. 5: 278. 1834. 
Aster lutescens T. & G. Fl. N. Am. 2: 160. 1841. 
Aster ptarmicoides lutescens A. Gray, Syn. Fl. 1°: 199. 1888. 
The color of the rays, yellow or ochroleucous as it has been 
described, is probably of little value specifically and may vary ; 
but in the specimens seen the bracts are “very obtuse” as 
described in Torrey & Gray’s Flora, the inner even rounded at 
the apex and therefore different from those of the typical U. alba. 
The range of this species seems to be more restricted than that of 
U. alba, extending from Illinois and Wisconsin to Saskatchewan. 
v Doellingeria pubens (Gray) Rydb. sp. nov. 
Aster umbellatus pubens A. Gray, Syn. Fl. 1°: 197. 1884. 
This I think specifically distinct from D. uméellata (Mill.) Nees. 
- Machaeranthera angustifolia nom, nov. 
Machaeranthera linearis Rydb. Mem. N. Y. Bot. Gard. 1: 398. 
1900. Not M. linearis Greene. 1897. 
Machaeranthera leptophylia sp. nov. 
Biennial, cespitose at the base; stems slender, simple up to 
the inflorescence, green, sparingly puberulent, 3-5 dm. high; 
