
4 
1901 | ROCKY MOUNTAIN PLANTS 4°99 
nearly linear, tapering downward, the scabrous pappus equaling 
the corolla tube. 
This excellent species was found growing in abundance on the wet, 
meadow-like banks of a mountain streamlet at an altitude of 8000 feet. The 
nearest ally known to me is A. ocreata Aven Nelson, from which it differs in 
its pubescence and wholly different disposition of its leaves. The habit of 
the inflorescence, too, is very unlike, which in the species now proposed con- 
sists of subequal heads always corymbosely disposed. 
No. 7643, Tie city, Albany county, July 20, 1goo, is the type. 
Arnica rhizomata, n. sp.—Conspicuously rhizomatous, the 
creeping rootstocks slender, sheathing-bracteate at the nodes, 
giving rise at intervals to the erect leafy stems and a few fleshy 
roots: pubescence whitish, soft, almost arachnoid, minutely 
granular-glutinous underneath the pubescence on the inflores- 
cence: stems 2-5“ high: leaves 5—7 pairs, rather uniformly dis- 
tributed, oblong-lanceolate, from obtuse to acute; the lowest 
pair with short scarious-margined petioles, early deciduous; the 
next I or 2 pairs 6-g™ long, about 2™ broad, on short mar- 
gined petioles which dilate at base to form the short ocreae; 
the upper pairs sessile, shorter: heads 3-5, 10-12™™" high, or 
Sometimes more numerous and then smaller: peduncles mostly 
short, erect, the lateral often exceeding the terminal : involucre 
campanulate, the bracts much shorter than the disk, narrowly 
oblong, obtusish: corolla long-pubescent on the tube, sometimes 
a few straggling hairs on the lobes: akenes linear, almost glab- 
Tous, the pubescence short and scattering, half as long as the 
8™" corolla: pappus fulvous or dirty-white. 
This species has been collected several times and has been held as a 
form of 4. foliosa, or rather as variety zacana. Such a disposition is 
no longer tenable, neither am I able to refer it to the species (A. foliosa 
utt.). It seems rather to belong to a section of which A. ocreata, A. celsa, 
and this are the principal members. In so far as this region is concerned, 
the following collections répresent it: 8012, Lincoln gulch, Albany county, 
August 8, 1900 (type); 1417, B. C. Buffum, Pine creek, 1892; Green moun- 
tain, July 6, 1896; 3587, North Vermillion creek, July 17, 1897. 
UNIVERSITY oF WYOMING, 
Laramie, Wyo. 
