430 CONTEIBUTIONS FROM THE NATIONAL, HERBARIUM. 



The flower heads are conspicuous and rather attractive; they last all summer. It 

 is probably this plant (or perhaps it is one of the species of Aniennaria) that is seen by 

 tourists, who repfort that they have found on one of the trails edelweiss "exactly like- 

 what I saw when I was in Switzerland." It is scarcely necessary to state that no 

 plant -^vith a very close resemblance to edelweiss is found in the Rocky Mountains. 



11. GNAPHALITJM L. 



Annuals, biennials, or perennials, with white-woolly pubescence; leaves alternate,, 

 narrow, entire; heads without rays, in small dense clusters, the bracts papery; pappus 

 of slender bristles. 



Plants biennial, 50 to 80 cm. high; heads nearly glabrous, the clusters not leafy. 



1. G. macounii. 

 Plants annual, 5 to 15 cm. high; heads woolly, the clusters surrounded by leaves. 



2. G. palustre. 



1. Gnaphalium macounii Greene. Tall cudweed. At low altitudes, infrequent; 

 in thin woods or on dry open slopes. B. C. to Ariz., Pa., and N. S. (G. decurrens 

 Ives.) — Plants solitary, with 1 or few slender stems; leaves linear or oblanceolate, 4 

 to 10 cm. long, the upper surface becoming green, covered with small glands: heads- 

 5 mm. high, sometimes in broad panicles, the bracts yellowish white. 



2. Gnaphalium palustre Nutt. Low cudweed. East entrance, in open moist 

 ground, frequently about ponds on prairie. B. C. to Calif., N. Mex., and Nebr. — 

 Plants loosely woolly, usually much branched; leaves spatulate or oblanceolate, 1 tO' 

 2 cm. long, woolly on both sides; heads 3 to 4 mm. high, in small woolly clusters, the 

 bracts brownish white. 



12. ADENOCATJLON Hook. 



1. Adenocaulon bicolor Hook. Pathfinder. Abundant on the west slope at 

 low and middle elevations; local on the east slope, frequent about Sun Camp, but 

 apparently absent in the Many Glacier region; in dry or moist woods or thickets. 

 B. C. to Calif., Mont., and L. Superior. — Perennial, with rootstocks, 0.3 to 1 meter 

 high; leaves alternate, triangular and heart-shaped, 5 to 20 cm. long, thin, green on 

 the upper side, white-woolly beneath, with low rounded teeth; heads about 3 mm. 

 long, the 4 or 5 bracts spreading in fruit; flowers pure white; achenes bearing small 

 stalked glands, spreading. 



A characteristic plant of the west slope. The very sticky achenes adhere readily 

 to clothing. 



13. IVA L. 



1. Iva xantliifolia Nutt. Reported from Belton by Jones. Wash, to N. Mex. and 

 Mich. (Cydarhacna xanthifolia Fresen.) — Coarse annual, about 1 meter high; leaves 

 mostly opposite, petioled, ovate, 5 to 10 cm. long, toothed, rough-hairy; heads 

 panicled, 4 to 5 mm. broad, the flowers greenish yellow; achenes without pappus. 



14. AMBROSIA L. Ragweed. 



Annuals or perennials, strong-scented; leaves mos^tly opposite, divided into narrow 

 lobes; flowers greenish yellow, in small heads, the staminate and pistillate in separate 

 heads; rays none; achenes hard, with a few short spines; pappus none. 

 Plants perennial, with rootstocks; leaves once lobed, the lobes usually toothed. 



1. A. psilostachya. 

 Plants annual; leaves twice lobed 2. A. elatior, 



1. Ambrosia psilostachya DC. Western ragweed. Waste ground about Belton 

 and east entrance; rare and evidently introduced. Calif, to La. and 111. — Plants 20- 

 to 60 cm. high, with short appressed hairs; leaves thick, with broad lobes; achenes 

 often unarmed. 



