AND GENERA OF PLANTS. 401 



Artemisia biennis, (Willd.) 



Hab. On the plains of the Platte, and in the Rocky Mountains. 



Artemisia pijchnostachya, (Decand.;) herbaceous, every where softly and 

 canescently lanuginous; leaves pseudopetiolate, bipinnately dissected; seg- 

 ments fastigiate, oblong, acute, simple, or partly subdivided ; panicle racemose, 

 very long, and of nearly equal breadth, many-flowered ; capitulum sessile, sub- 

 globose, erect, about ten-flowered; sepals lanceolate, all lanuginous. 



Hab. On the sea-coast of Monterrey, Upper California. A species with almost the foliage of A. 

 Absinthium, but very soft and lanuginous with somewhat spreading hairs. Perennial, Avith a 

 running root. Panicle two or more feet long; branches short, the flowers clustered. (1 have only 

 seen the winter vestiges of this curious species.) 



Artemisia *PaciJica; herbaceous, soft, and canescently sericeous; leaves 

 pseudopetiolate, bipinnately dissected, the segments often trifid, oblong or 

 linear, acute; stem leaves pinnately dissected, pseud ostipulate on the infertile 

 shoots; stem and ovate, pedicellate capitulum, smooth. 



Hab. Shores of the Pacific, at the outlet of the Oregon, in sandy places. Considerably allied to 

 A. canadensis, but more tomentose, with broader and fewer segments to the leaves, the radical and 

 lower leaves very much as in the last species. Perhaps A. desertorum, y. Scouleriana of Hook. 

 Flor. Bor. Am., p. 325. 



TANACETUM. (Lessing.) 

 Tanacetum Huronetise, Nutt, Gen. Am., Vol. II., p. 141. T. Bouglasii, 

 Decand. Prod., Vol. VI., p. 128. Omalanthus camphoratus, Hook. Flor. Bor., 

 Vol. I., p. 321. O. camphoratus? Less. 



Hab. Coast of the Pacific to California; common. Rays and disk pale yellow, the former 

 scarcely exserted. 



Tanacetum ^horeale; softly hairy; leaves and segments also bipinnatifid, 

 apiculate, rachis leafy, the leaflets pinnatifid; corymb few-flowered, (four to 

 five;) sepals lanceolate, the inner with brown, scariose margins; rays conspi- 

 cuous, three-lobed. 



Hab. Arctic America, (Hooker.) Apparently not the T. pauciflorum, in which the flowers are 

 said to be all hermaphrodite, and the plant very smooth. 



*SPH7ER0MERIA. 



Capitulum many-flowered, discoid, heterogamous ; florets all tubular, the radial 

 feminine, (about five,) truncate, two or three-toothed; discal florets herma- 

 phrodite, shortly five-toothed; style bifid, stigmas truncate, and minutely 

 VII. — 5 a 



