384 University of California Puhlications in Botany [Vol. 9 



(Transition zone), R. scahrida, Eastwood of the Coast Ranges, and 

 R. Pringlei Greene of the mountains of northern California, the latter 

 species being, however, very doubtfully distinct from R. scaposa. 



20. ARNICA 



Leaves uniform in shape; all narrowed to a petiole (usually winged) or sessile. 

 Hears large (involucres %-% inch high), solitary or few (2-3), on long 



leafless peduncles 1. A. nevadensis 



Heads medium sized (involucres %-% inch high), usually several on 



peduncles with 3 or m.ore pairs of leaves which are not much diminished 



in size upward. 



Plants whitened with soft floccose tomentum; lower leaves with connate 



bases sheathing the stems and palmately nerved with 3 or 5 principal 



nerves 2. A. foliosa var. incana 



Plants green; leaves pinnately veined. 



Stems numerous, clustered; leaves narrow (%-% inch wide), 3-6 inches 

 long, lanceolate-acuminate, widest in the middle; achenes minutely 



glandular but not hairy 3. A. longifolia 



Stems solitary or few; leaves broader (%-% inch wide), oblong lanceo- 

 late to ovate, obtuse or only acute; achenes hairy, at least at first. 



Leaves entire to repand dentate, soft pubescent 4. A. mollis 



Leaves saliently and acutely dentate, nearly glabrous above and 



often glandular 5. A. amplexicaulis 



Leaves of 2 kinds: the upper cauline sessile, lanceolate; the usually obtuse 

 lower leaves petioled and cordate or subcordate at base. 

 Plants with harsh, viscid-glandular pubescence or nearly glabrous; lower 

 leaves sharply dentate, short petioled; heads larger than in the next 



6. A. latifolia var. viscidula 



Plants with hirsute or villous pubescence, not viscid-glandular; lower leaves 

 serrate or dentate 7. A. cordifolia 



1. Arnica nevadensis Gray, Proc. Am. Acad., vol. 19, p. 55. 1884. 



Type locality. — ^"California, collected several years ago on Las- 

 sen's Peak." 



Range. — Sierra Nevada and northward to the mountains of Lassen 

 County and perhaps in the Mt. Shasta region. 



Zone. — Canadian mainly, but found both above in the Hudsonian 

 and rarely below in the Upper Transition. 



Specimens examined. — Mt. Stanford (Castle Peak), 8,400 feet, 

 Sonne, July 17, 1887 ; same locality. Dr. Kellogg, July 29, 1870 ; Glen 

 Alpine, Tahoe, Setchell and Dobie, July 6-21, 1901; about Fallen 

 Leaf Lake, Tahoe, M. S. Baker, July 3, 1904 ; near Suzy Lake, Talioe, 

 7,900 feet, Smiley 168; Mt. Tallac, gravel among rocks to summit, 

 Hall and Chandler 4613 ; head of Fall Creek, Ormsby County, Nevada, 

 2,460 m.. Baker 1432 ; Rubicon Peak, Tahoe, 8,700 feet, Smiley 403 ; 

 Angora Peaks, Tahoe, 7,500 feet. Hall 8796; Carson Spur, Alpine 

 County, 8,500 feet, Hansen 410; Mt. Dana, 10,000 feet. Hall and 

 Babcock 3599 ; peak N.E. of soda springs, Tuolumne River, 9-10,000 

 feet, State Survey 1808. 



