COMPOSITE. 397 



S2. PLUCHEA, Cassini. Herbs or shrubs with alternate leaves, and 

 terminal cymose clusters of smallish heads; these many-flowered, the 

 flowers largely pistillate only, their corolla reduced to a slender truncate 

 or 2 — 3-toothed tube, that of the hermaphrodite (but sterile) flowers 

 regularly 5-cleft. Acheues small, 4— 5-augled or sulcate. Pappus a 

 series of capillary bristles. 



1. P. ('aiiiphonitsi, DC. Prodr. v. 452 (1836); Linn. Sp. PL 2 ed. 1212 

 (1763), under EHgeron. Annual, stoutish, leafy, 2 ft. high; minutely and 

 somewhat viscidly pubescent: leaves oblong-ovate to oblong-lanceolate, 

 acute at both ends, toothed or denticulate, the larger (3 — 5 in.) petioled: 

 heads short-pedicelled, dull-purple, crowded in a corymbiform cluster: 

 involucral bracts ovate to Iruceolate, often tinged with the dull pale 

 purple of the corollas. — Borders of brackish marshes. Aug. — Oct. 



2. P. borealis. Gray, Proc. Am. Acad. xvii. 212 (1882); T. & G., 

 Emory's Rep. 143 (1848), under Tessaria. Shrub 6 ft. high more or less, 

 with suberect slender and flexible willowy branches, very leafy up to the 

 cymose clusters of smallish heads: leaves silky-pubescent, 1 — 2 in. long, 

 linear-lanceolate, entire, acute at both ends: involucre campanulate; 

 outer bracts ovate, obtuse, tomeutose; inner ones narrowly linear, decid- 

 uous: corollas whitish, with a tinge of purple or red: pappus copious, 

 the bristles uf the infertile flowers clavellate-dilated, of the fertile ones, 

 more slender. — Banks of streams, from San Luis Obispo Co. southward. 



33. ANTEXXARIA, G:nimr. Tufted or matted white-woolly peren- 

 nials with alternate entire leaves, and solitary or corymbose small heads 

 of white or pinkish flowers, the plants all unisexual. Pistillate plants 

 with filiform triancate corollas shorter than the 2-cleft style; staniinate 

 with 5-cleft corollas and truncate undivided style. Pappus a single 

 series of capillary bristles; those of fertile flowers accrescent, very 

 slender, connate at base; those of the sterile flowers mostly thickened at 

 apex. Achenes small, terete or flattish. 



* Radical leaves larger, those of the scape-like stems reduced in number 



and size. 



■^ Stents witli stolon-like leafy sterile shoots from the base. 



1. A. (IJoioa, Gc-ertn. Fruct. ii. 410 (1791); Linn. Sp. PI. ii. S50 (1753), 

 under Gnaphalmin. Gregarious, by multiplication of radical shoots, and 

 forming broad mats, with rosettes of spatulate or oblanceolate silvery- 

 tomentose leaves : scapiform stems 2 — 10 in. high, bearing mostly linear 

 leaves, and several heads in a close corymb: bracts of involucre with 



