AND GENERA OF PLANTS. 345 



Hab. Near St. Diego, Upper California. Not more than six inches high, very softly and co- 

 piously pubescent; segments of the leaves crowded. Stem slender, simple, scarcely extending 

 beyond the bosom of the radical leaves ; male spike about two inches long ; involucrura about ten 

 or twelve-flowered, five-toothed; receptacle with linear palea, pubescent at the tips. 



Franseria * discolor; il, root creeping; leaves interruptedly bipinnatifid, 

 above nearly smooth, canescently and closely tomentose, segments subovate, 

 acute, confluent in the vv^ide rachis; stem short, with the lateral branches de- 

 cumbent. 



Hab. In the Rocky Mountains, near the Colorado of the West. A very remarkable and dis- 

 tinct, as well as elegant species. Stem about a span long, slightly pubescent; leaves on long pe- 

 tioles, with a lanceolate outline, acute, about six inches long, white beneath, green above, the pin- 

 natifid segments lanceolate, the rachis incisely toothed. Male florets rather numerous; receptacle 

 with narrow, pubescent palea; involucrum about five or six-toothed; female flowers few, fruit 

 spiny. 



Franseria *cuneifolia; 2/, softly sericeous and somew^hat canescent; stem 

 simple, decumbent, pilose ; leaves cuneate-oval, dentate, long petiolate, three to 

 five-nerved at base; male florets very numerous, the scales hirsute at the tips; 

 spines of the fruit rigid, sublanceolate ; male involucrum ten to twelve-toothed. 

 — F. Chamissonis ? liEssma, Decand., Vol. V., p. 524. 



Hab. Outlet of the Oregon, near the sea. A very remarkable species. Stem succulent, about 

 two feet long, many from the same root ; leaves about an inch wide, two and a half to three inches 

 long, the peduncle as long as the leaf. Fruit axillary, crowded, and, as in F. bipinnatifida, 

 glandular, w^ith resinous atoms. Achenium large, oblong-oval. — In all the preceding species the 

 corolla is five-toothed. 



§ * Ambrosidium. — o Palea of the receptacle very slender and deciduous. 



Franseria *montana; o, scabrous, and somewhat canescent with appressed 

 hairs; stem branching, flowers paniculate, racemes lateral and terminal; leaves 

 bipinnatifid, confluent towards the summit, segments oblong or subovate, ab- 

 ruptly acute; involucrum five to eight-cleft, naked, about ten to twenty -flow- 

 ered ; fruit ovoid, thickly covered with long, smooth, flat spines. 



Hab. In the Rocky Mountains, near the Colorado of the West, One to two feet high; stem 

 scabrous, leaves softish to the touch, with closely appressed hairs ; chafl" of the involucrum decidu- 

 ous, or wanting, rachis of the leaves wide. 



Franseria Hookeriana. Ambrosia acanthocarpa; Hook. Flor. Bor. Am., Vol. 

 I., p. 309. Distinguished from the preceding chiefly by the few linear seg- 

 VII. — 4 M 



