AND GENERA OF PLANTS. 383 



*DICH^TA. 



Capitulum many-flowered, heterogamous; rays feminine, oblong, two-toothed. 

 Discal florets hermaphrodite, five-toothed, with a campanulate summit, 

 smooth. Stigmas subcapitate, obtuse, pubescent. Involucrum subcampa- 

 nulate, five to twelve-leaved, in a single series; sepals ovate, ciliate, the same 

 number with the rays. Receptacle conic, narrow and elevated, papillose. 

 Achenium narrow and acutely conic, angular. Pappus in ray and disk 

 similar, of about eight obtuse, small, fimbriated scales, and two, rarely three 

 or four, intermediate, separate awns. — Annuals, with opposite, entire, or 

 laciniately pinnatifid leaves; flowers terminal, pedicellate, yellow, almost 

 exactly like those of Burrielia, but the plant subaquatic, and with a very 

 different pappus. — (The name from the intermediate pappus of mostly two 

 awns.) 



Dichceta *tenella; erect, stem simple, pilose; leaves linear, mostly entire, the 

 lower ones somewhat laciniated; rays and sepals five to eight. 



Hab. On the margins of ponds and wet places. St. Barbara, Upper California. Flowering in 

 April. A slender, diminutive plant three or four inches high. Leaves an inch or more long, about 

 a line wide. Rays scarcely as long as the disk. 



Dichceta *uliginosa; decumbent and branching; stem, peduncles, and often 

 the involucrum hairy; leaves laciniately pinnatifid, with a broad rachis, the 

 segments linear; rays about eight to twelve, shorter than the disk. 



Hab. With the above, but a much larger plant, and almost aquatic. Awns of the pappus 

 sometimes three or four. Leaves two to three inches long with a broad rachis, sending off very un- 

 equal, linear, narrow, acute segments. 



LASTHENIA. (Cassini.) 



§. HoLOGYMNE. — Rays oblong, conspicuous, as long as the disk. Achenia 

 compressed, linear-oblong, glandularly scabrous, and without pappus. — An- 

 nual, subaquatic, or terrestrial herbs, with opposite, entire, linear leaves. 

 Flowers yellow, terminal, pedicellate. 



Lasthenia glahrata, Decand., Vol. V., p. 665. Decumbent or erect, and 

 branching from the base; smooth, except the pedicels; rays twelve to fifteen, 



