COMPOSITJE. 411 



3. H. NeTadensis, Greene, Bull. Calif. Acad. i. 89 (1885). Rigidly 

 erect, 2 ft. liigh, the stems beariug at summit 3 or more short-peduncled 

 heads: leaves lanceolate, the upper mostly alternate: achenes narrower, 

 less obcordate than in the foregoing, obovate-oblong in outline: pappus 

 of 2 short persistent awns and several equally persistent intermediate 

 squamellsQ.— Plentiful at subalpine elevations in the Sierra Nevada. 

 July — Sept. 



53. BIDENS, Tourneforl. (Beggar Ticks.) Branching herbs with 

 opposite leaves, the heads with double involucre, the outer series of 

 bracts foliaceous and spreading, the inner membranaceous and erect. 

 Achene bearing a pappus of 2 or more rigid retrorsely hispid or aculeate 

 awns. 



1. B. frondosa, Linn. Sp. PI. ii. 832 (1753). Somewhat hairy, 2 6 ft. 

 high: leaves pinnately 3 — 5-divided into lanceolate-serrate petiolulate 

 leaflets: involucre often very leafy: rays inconspicuous: achenes obovate 

 or oblong, 2-awned. — Fields of the lower Sacramento, and southward. 

 Aug.— Oct. 



2. B. laevis, B. S. P. Cat. N. Y. 29 (1888); Linn, under Helianthm. 

 Glabrous, stout, more or less decumbent, 1 — 2 ft. high: involucre not 

 leafy, surpassed by the oval inch -long yellow rays: achenes often with 

 more than 2 awns. — In very wet grounds only, near lakes and rivers. 

 Aug. — Nov. 



54. LEPTOSYNE, DeCandolle. Glabrous annuals, perennials, and 

 half-shrubby plants, with dissected foliage, and usually long scapiform 

 erect peduncles bearing showy heads of yellow flowers. Involucre 

 double; an outer series of narrow foliaceous spreading bracts, and an 

 inner of broad membranaceous erect ones. Rays broad. Chaff of recep- 

 tacle linear, thin, scarious, deciduous with the fruit. Achenes flat, 

 or somewhat concavo convex, margined. Pappus a minute callous cup, 

 or a pair of palete. 



* Loiv annuals, mostly almost stemless. 

 ■*— Achenes callous-winged and meniscoid. 



1. L. Douglasii, DC. Prodr. v. 531 (1836). Leaf-divisions filiform: 

 peduncles slender; head an inch wide: achenes sparsely beset with capi- 

 tate rigid bristles, the margin at length corky; cup-like ring in place of 

 the pappus entire. — Attributed to the vicinity of San Francisco; perhaps 

 erroneously; common from Monterey southward. 



