408 DESCRIPTIONS OF NEW SPECIES 



to four or five inches in height. There are no infertile filaments in the ray, and the pappus is 

 almost perfectly plumose. 



Arnica *macrophylla; slightly pubescent; stem about three-flowered, with 

 three pairs of leaves ; radical and lower petiolate stem leaves, cordate, acute, the 

 radical often obtuse, irregularly and somewhat incisely dentate, uppermost pair 

 small lanceolate, semiamplexicaule, acuminate; pedicel elongated, bracteate; 

 sepals linear-lanceolate, acute, about twelve, hirsute at the base; rays without 

 filaments. 



Hab. In the valleys of the Blue Mountains of Oregon. Stem about twelve to eighteen inches 

 high; the leaves distant from each other, the lowest two to three inches wide, and about the same 

 in length ; the petioles longer than the leaves, which with the lower part of the stem are more or 

 less pilose. Rays pale yellow, about twice the length of the involucrum. Discal florets with the 

 dentures hirsutely pilose at the tips. Achenium subcylindric, hirsute ; the pappus nearly plumose. 

 Veins of the leaves coarsely reticulated. 



Arnica *ainplexicaulis; nearly smooth; many stems from the same root; 

 leaves five or six pairs, approximate, ovate, acute, amplexicaule, denticulate; 

 capituli three to five, lateral and terminal; sepals about twelve, linear-lanceo- 

 late, acuminate; rays without filaments; achenium hirsute. 



Hab. On the rocks of the Wahlamet, at the Falls. About a foot high, and very leafy; the leaves 

 nearly all equal, except the uppermost floral pair: lateral branches leafy, one-flowered; rays longer 

 than the involucrum, nearly linear, three-toothed, the teeth small; tips of the involucrum purple. 

 Pappus nearly plumose. 



SENECIO. (Lessing.) 

 t Discoidal species. 



Senecio "^delilis; %, glabrous; lower leaves upon very long petioles, radical 

 spathulate-oval, obtuse, entire, or incisely toothed at base, cauline few, amplex- 

 icaule, pinnatifid; segments oblong, remote, entire or sparingly toothed, the 

 upper ones with a tuft of down at the base; corymb simple or compound; in- 

 volucrum minutely bracteolate; sepals about twenty, not sphacelate; florets 

 with the teeth glabrous; achenium smooth. 



Hab. Plains of the Oregon, near the Wahlamet. Nearly allied to S. elongatus, of Pursh. 

 Lower leaves with petioles three or four inches long, the primary ones quite entire and obtuse, at 

 length toothed, and finally pinnatifid, with clasping auricles ; umbell usually twice compounded, 

 the umbells with three to five heads, the proper pedicels rather short; florets bright yellow. Lower 

 leaves often greatly resembling those of Barharea vulgaris, the pinnatifid ones remarkable for the 

 remoteness and shortness of their lobes, which are mostly entire. 



