106 Proceedings of the Biological Society of Washington. 



obtuse, coarsely irregularly serrate, 2-5 cm. long, the lower pair short 

 petioled, the upper pair sessile and larger ; heads three, long-peduncled from 

 a lanceolate acute dentate sessile green bract ; heads campanulate, rayless, 

 1.5 cm. high, 1 cm. broad; tegules 8, linear-lanceolate, acuminate, shorter 

 than the flowers, glabrous; disk flowers about 25, each 1 cm. long; pappus 

 bright white, barbellulate ; akenes cylindric, glabrous. 



Mount Baker, Washington, G. W. Turesson in 1915. Closely allied to 

 A . latifolia Bong, and A . betonicaefolia Greene but rayless. 



Arnica andersonii, n. sp. 



Stems erect, 30-50 cm. high, very sparsely pubescent, simple or more 

 commonly with a flowering branch in the axil of each cauline leaf; basal 

 leaves with petioles as long as the blades, the latter thin, oblong to narrowly 

 ovate, acute, abruptly narrowed at base, coarsely few-toothed, glabrous 

 except the ciliolate margins, 6 to 8 cm. long; cauline leaves two pairs, the 

 lower pair similar to the basal and petiolate, the upper sessile and usually 

 conspicuously contracted at base; heads nodding in bud, large, each sub- 

 tended at base by a pair of more or less modified leaves; involucre cam- 

 panulate, 1.5 cm. broad; tegules 10, green, thin, lanceolate, acute, viscidly 

 pubescent, 1.5 cm. long; rays about 10, lemon-yellow, 3 cm. long; disk 

 florets 11-13 mm. long; akenes hirsutulous, 6-8 mm. long; pappus bright 

 white, copious, short-plumose. 



Skeena, Br. Col., /. R. Anderson, Sept. 11, 1910. Allied to A. cordifolia 

 Hook, but differing particularly in the basal leaves and the pair of folia- 

 ceous bracts at the base of each head. 



Arnica myriadenia, n. sp. 



Stems clustered from a much branched caudex, erect, 30-50 cm. high, 

 densely and minutely glandular, becoming increasingly hirsutulous toward 

 the heads; basal leaves apparently none; cauline leaves 4 or 5 pairs with 

 green blades and 2 or 3 basal pairs much reduced and more or less scarious, 

 all sessile and connate at base, the lower ones conspicuously sheathing, 

 lanceolate becoming narrower upwards, acute, entire or sparingly den- 

 ticulate, densely and minutely glandular on both faces and somewhat 

 puberulent especially on the margins, 4-12 cm. long, exceeding the inter- 

 nodes; heads 3 to 5, hemispheric, 2 cm. broad, short peduncled; tegules 

 about 11, lanceolate, acuminate, green, densely glandular and somewhat 

 puberulent, equalling the disk flowers; rays bright yellow, 1.5 cm. long; 

 disk flowers 40-60; pappus brownish, barbellulate; akenes sparsely his- 

 pidulous, not glandular; plant strongly odorous. 



Mount Rainier National Park, Washington, growing in talus on Owy- 

 high, 5700 feet altitude, J. B. Flett No. 3211, August 13, 1919. The 

 plant was found in no other place. 



