MADIACE^E. 191 



2. H. castanea, Greene. Stouter, seldom a foot high, rough-pubes- 

 cent with short spreading hairs: leaves scabrous, lanceolate, nearly 

 equalling the stem; heads nearly 2 in. wide; rays 1 in. long: achenes 

 cuneate-obovate, neither strongly compressed nor thin-edged, those of the 

 ray thicker and triquetrous, all dull-black at base, chestnut-brown above 

 the middle; apical notch short and deep. — Summit of Mt. Diablo. 



36. LEPTOSYNE, DeCandolle. Low glabrous annuals, with an 

 apparently radical tuft of leaves cut into linear lobes, and long scapiform 

 erect peduncles bearing each a showy head 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 

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

 margined. Pappus a minute callous cup, or a pair of palese. 



1. L. Douglasii, DC. Peduncles slender; head an inch wide: achenes 

 sparsely beset with capitate 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. 



2. L. Stillmaiii, Gray. Less strictly acaulescent: achenes nearly 

 smooth and glabrous, the corky margin rugose; terminal cup sometimes 

 2-lobed. — At Alma, Santa Clara Co., according to Dr. Behr. 



3. L. calliopsidea (DC), Gray. Stoutish and somewhat leafy above 

 the base: bracts of outer involucre thick, broadly ovate, little shorter 

 than the narrowly ovate inner ones: rays often 1 in. long and % in. wide: 

 ray-achenes distinctly thin-winged; disk-achenes cuneale-oblong , long- 

 villous on the margins and inner face; pappus of 2 long and conspicuous 

 palese. — Santa Clara Co., Behr. 



37. BIDENS, drsalpinus. Branching herbs with opposite leaves, 

 the heads with double involucre as in Leptosyne. Achene bearing a 

 pappus of 2 or more rigid retrorsely hispid or aculeate awns. 



1. B. frondosa, L. 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. Aug. — Oct. 



2. B. Isevis (L.), BSP. 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. 



Suborder 6, Madiaob*. 



Herbs with watery juice, but herbage mostly viscid and glandular. 

 Involucre of a single series of equal bracts. Ray-flowers fertile, the 

 achene of each embraced by or enfolded within its involucral bract. Chaff 



