COMPOSITAE. 385 



Arnica gracilis Rydb. Herbage minutely atomiferous glandular; stems 

 slender, 15-30 cm. high; basal leaves ovate, dentate, 3-ribbed, slender-petioled; 

 cauline leaves in 2 pairs, similar, the upper sessile; heads 13; ray-corollas 

 bright yellow, 15 mm. long; akenes minutely glandular. 



Olympic Mountains, Lamb, Piper. 



Arnica latifolia Bong. Glabrous or nearly so; stems erect, 30-60 cm. high, 

 from slender rootstocks; leaves all opposite, the lower petioled, cordate or 

 subcordate, coarsely dentate; cauline leaves 2 or 3 pairs, oval to ovate, sessile 

 by a broad base; heads long-peduncled; involucre campanulate, sparsely 

 pilose to nearly glabrous; tegules about 13, oblong-obovate, acuminate, 1 cm. 

 long; ray-flowers dark yellow, 1.5-2 cm. long; akenes glabrous. 



Common along alpine streams. 



Arnica betonicaefolia Greene. Nearly glabrous; stems slender, 6-15 cm. 

 high; leaves oval to oval-lanceolate, obtuse, crenate-dentate, 2-3 cm. long, the 

 basal ones petioled, the 2-3 pairs of cauline sessile; heads 1-3, long-peduncled; 

 involucre 10 mm. high, turbinate; tegules pubescent, acute; ray-flowers 

 11.5 cm. long; akenes sparsely hairy at top; pappus white. 



In alpine meadows at about 2000 m. altitude. The type specimens are 

 from Mount Steele in the Olympic Mountains. 



Arnica eradiata (Gray) Heller. (A. parryi Gray.) Hirsutely pubescent, 

 glandular toward the top; stems mostly simple, 30-50 cm. high; leaves oval to 

 ovate-oblong, denticulate, the basal ones petioled; cauline 1-3 pairs; heads 

 rayless, solitary or often 3-5; involucre 10-12 mm. high; tegules hirsute and 

 glandular; akenes glabrous or sparsely hirsute. 



In alpine meadows at about 2000 m. altitude. 



Arnica fulgens Pursh. Erect, 30-60 cm. high, the crown thickened and 

 rusty- woolly, sometimes with creeping rootstocks; whole plant viscid-pubes- 

 cent; basal leaves spatulate-lanceolate, 3-nerved, entire or nearly so, obtuse, 

 5-12 cm. long; cauline 2 or 3 pairs, sessile, the upper sometimes very small; 

 heads 1-3, long-peduncled; involucres 10-12 mm. high, densely glandular- 

 pubescent; ray-flowers yellow, 12-16 mm. long; tubes of disk-corollas hairy; 

 akenes pubescent. 



A species of the interior, rare in our limits; Goat Mountains, Allen. The 

 subterranean characters may vary according to soil; the form without root- 

 stocks has been named as a species, A. pedunculata Rydb. 



Arnica aurantiaca Greene. Tufted, 5-20 cm. high; stems erect, bearing 

 1-3 heads; cauline leaves 2 or 3 pairs, entire, the lowest oblong, obtuse, the 

 upper oblong-lanceolate, acute, glabrous except the margins; peduncle sparsely 

 glandular and pubescent; involucre turbinate-campanulate; tegules about 10, 

 lanceolate, woolly at base, thinly ciliate; ray-flowers orange-yellow; akenes 

 silky; pappus white. 



Goat Mountains, Allen. 



Arnica amplexicaulis Nutt. Nearly glabrous and somewhat gummy ; 

 stems 30-60 cm. high, tufted; leaves ovate, acute, saliently dentate, glabrous 

 and gummy above, 4-7 cm. long; basal ones petioled; cauline 4-7 pairs, half- 

 clasping at base; heads mostly 3 or 5; ray-flowers 1-1.5 cm. long; akenes hairy. 



Along streams, especially in the mountains at low altitudes. First col- 

 lected at Willamette Falls, Oregon, by NuttalL 



Arnica macounii Greene. Sparsely pubescent; stems tufted, 30-50 cm. 

 high; leaves lanceolate or oblong-lanceolate, acute, serrate-dentate, 5-10 cm. 

 long, the basal ones petioled, the 4-7 cauline pairs sessile; heads cymose, usually 

 5-7, on small stems 1-3; involucre campanulate; tegules hispidulous, not 

 glandular; akenes hispid and glandular; pappus fuscous. 

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