436 CONTRIBUTIONS FROM THE FATIONAl, HERBARIUM. 



10. Arnica fulgens Pursh. Collected along Kennedy Creek by Weller. B. C. to 

 Calif., Colo., and S. Dak. (A. pedunculata Rydb.) — Stems 20 to 40 cm. high, hairy; 

 leaves mostly basal, oblong to linear-lanceolate, 5 to 10 cm. long, finely hairy, entire; 

 heads 1 or 3, 12 to 15 mm. high. 



11. Arnica alpina (L.) Olin. Common above timber line, on rock slides or rocky 

 elopes or in meadows. Alaska to Wash., Colo., Alta., Lab., and Greenl.; also in Eur.— 

 Stems 10 to 20 cm. high, somewhat hairy; stem leaves 1 to 3 pairs, mostly lanceolate, 

 toothed or entire; heads 1 to 3, about 1 cm. high. 



12. Arnica tomentosa Macoun. Open rocky slopes and summits at Piegan Pass and 

 Sexton Glacier. B. C, Alta., and Mont. — Stems 8 to 12 cm. high, densely woolly; 

 stem leaves 1 or 2 pairs, lanceolate, entii-e; head 1, 10 to 12 mm. high. 



26. SENECIO L. Ragwort. 



Perennials or rarely annuals; leaves alternate, entire, toothed, or lobed; heads 1 

 to many, with conspicuous yellow rays (except in one species); involucre composed 

 of one series of equal (not overlapping) linear bracts, with a few short bracts at the 

 base; achenes very narrow, with pappus of soft white bristles. 



Plants annual ; rays none 1. S. vulgaris. 



Plants perennial ; rays present. 



Heads about 2.5 cm. high 2. S. megacephalus. 



Heads less than 1.5 cm. high. 



Lowest leaves entii-e, densely white-woolly on both sides. 



Bracts about 21 3. S. canus. 



Bracts about 13 4. S. purshianus. 



Lowest leaves more or less toothed, green. 



Leaves triangular, sharp-pointed, toothed 6. S. triangularis. 



Leaves not triangular, often blunt-pointed, toothed or lobed. 

 Upper stem leaves not much if at all smaller than the lower ones; plants in 



small bushy clumps 6. S. fremontii. 



Upper stem leaves much smaller than the lower ones; plants erect, never in 

 bushy clumps. 

 Stem bearing 1 or rarely 2 heads. 



Heads and leaf stalks woolly at the base; leaves very thick and fleshy. 



7. S. conterminus. 



Heads and leaf stalks glabrous 8. S. ovinus. 



Stem bearing several or numerous heads. 

 Stem leaves toothed; lowest leaves sharp-pointed; bracts with dark 



tips 9. S. hydrophiloides. 



Stem leaves lobed; lowest leaves rounded at the tip; bracts not with 

 dark tips. 

 Leaves at base of stem mostly 2 to 3 cm. long, long-tapering at base, 



thick and fleshy 10. S. cymbalarioides. 



Leaves at base of stem mostly 4 to 7 cm. long, never long-tapering at 

 base, thin. 

 Lower leaves mostly broadly notched at base, the teeth usually low 



and blunt 11. S. pseudaureus. 



Lower leaves truncate to acute at base, the teeth mostly sharp and 

 spreading 12. S. burkei. 



1. Senecio vulgaris L. Weed in garden at Lewis's; reported from Bel ton by Jones. 

 Native of Eur.; naturalized in N. Amer. — Plants 10 to 40 cm. high, nearly glabrous; 

 leaves deeply lobed; heads 7 to 9 mm. high, the bracts with black tips. 



2. Senecio megacephalus Nutt. Frequent at middle and high altitudes, usually 

 on open slopes. B. C, Idaho, Mont., and Alta. — Plants 20 to 60 cm. high, usually in 

 dense clumps; leaves oblanceolate or oblong, 5 to 20 cm. long, thick, woolly at 



