AND GENERA OF PLANTS. 307 



four slightly scabrous rays. Capituli sometimes as many as nine. The pe- 

 duncles and upper part of the stem, from the smallness of the leaves, appearing 

 almost naked. More or less puberulous. 



Erigeron purpureum. — Oregon and Upper California, common. 



/?. * attenuatum; stem elongated and slender towards the top, very hairy at 

 base; radical leaves spathulate-lanceolate, dentate; flowers white, the rays not 

 much longer than the disk. 



Hab. In Oregon and Arkansas Territory. Flowers white, and smaller than in E. purpureum, 

 the whole plant more hairy. Perhaps a species. 



Erigeron pumilum. 



Hab. Rocky Mountains of the Platte. Stems one to four-flowered, heads fastigiate. Pappus 

 single, of about twenty rays. 



Erigeron *helUdiastrum, O; stem leafy, corymbosely branched, hirsute; leaves 

 entire, linear-oblong, sessile, scabrous on the margin, attenuated below, the 

 radical ones slender; involucrum hemispherical, sepals lanceolate acute; rays 

 about the length of the disk. 



Hab. On the borders of the Platte, within the Rocky Mountains. About a foot high, the leaves 

 thickish and rather smooth, one to two inches long, two to four lines Avide. Rays pale red, about 

 as numerous as in the common daisy, rather short. Pappus simple, very deciduous, of about ten 

 rays ! The natural situation of this species is in the section Olygotrichium, but the pappus is 

 simple ; and hence it appears that the pappus does not define the natural limits either in this or 

 many other genera of CoMPOsiTiE. 



Erigeron * cczspitosum; csespitose, hirsute, and almost canescent with short 

 hairs; stems decumbent, many from the same root, mostly one-flowered; leaves 

 linear-sublanceolate, somewhat obtuse, those on the stem sessile, all entire; se- 

 pals lanceolate acute; rays longer than the disk; achenium elongated, smooth. 



Hab. On the summits of dry hills in the Rocky Mountain range, on the Colorado of the West, 

 Flowering in August. Nearly allied to E. Andicola. Equally hirsute, with close white hairs. 

 Leaves about one and a half to two inches long by two lines wide, those of the root clustered; on 

 the slender low stems few; stems occasionally two-flowered; involucrum short and hirsute. Rays 

 forty to fifty, rather wide, often three-toothed, white or pale rose. Pappus simple, of about twenty- 

 scabrous, slender bristles. An alpine species, with the flower as large as a daisy. 



