AND GENERA OF PLANTS. 429 



*RAFINESQUIA. 



Capitulum many-flowered. Involucrum subcylindric-conic, caliculate; sepals 

 equal in length, imbricated in about two series, linear and acuminate. Re- 

 ceptacle naked, puncticulate. Achenia subterete, subulate, scarcely striate, 

 somewhat rugose, terminating in a long, filiform rostrum; the external series 

 pubescent. Pappus plumose, in several series. — An annual, much-branched, 

 tall, smooth herb of Upper California, with the aspect of a Sonchus. Leaves 

 amplexicaule, runcinate-lyrate, flowers in loose corymbs; the branches mi- 

 crophyllus; caliculum rather short and spreading, the segments linear-subu- 

 late. Flowers small, white, externally dark purple in the centre of the 

 liguli. Allied apparently to Ti-agopogon, but very distinct in habit. — (Dedi- 

 cated to the memory of an almost insane enthusiast in natural history; some- 

 times an accurate observer, but whose unfortunate monomania was that of 

 giving innumerable names to all objects of nature, and particularly to plants.) 



Rafinesquia Califoridca. 



Hab. Near the sea-coast, in the vicinity of St. Diego, Uppei' California. An annual growing to 

 the height of two or three feet, and nearly erect. Stem terete, and pui-plish, somewhat divaricately 

 branched, branches fastigiate, tending to a corymb at the summit. Leaves more or less deeply 

 and runcinately pinnatifid, amplexicaule, lanceolate, and acute. Floral branches with minute 

 reflected leaves. Involucrum rather long, at first almost cylindric, but quickly enlarging at the 

 base, so as to become conic in the manner of the Sow Thistle. Sepals twelve to fifteen, all of the same 

 height, but in two series, with membranous margins ; the caliculum squarrose and short. Florets 

 very fugacious and small, only opening for a few hours, and but little exserted, toothed at the apex. 

 The outer row of achenia pubescent, with short appressed hairs, all somewhat rugulose, attenuated 

 into a rostrum about one and a half times its length, and slenderly filiform; the crown of pappus 

 copious, and softly plumose, the rays fragile. I have had this plant in cultivation in Philadelphia, 

 but it is now lost. 



Subtribe vii. LACTUCEiE. (Lessing., Decand.) 



PYRRHOPAPPUS. (Decand.) 



Obs. Achenium linear-oblong, muriculate, with five broad, appressed ribs, 

 and internally grooved. 



VII. — 5 H 



