1:38 COMPOSITAE. 



Lowes! foothills of the inner Coast Range in Solano Co.; Sierra Nevada foot- 

 hills. May-June. 



41. RIGIOPAPPUS day. 

 Slendei annual with alternate very narrowly Linear entire leaves. Heads 



small, solitary on the simple stems or on the branches, which are often 

 proliferous. Receptacle flat, naked, Bracts subulate, similar to the upper 

 Leaves. Flowers yellow. Ray-corollas not exceeding the disk, the ligule not 

 Longer than the tube. Disk-corollas small, with 3 to 5 short erect teeth. 

 Pappus in disk and ray of 3 to 5 subulate awns. Achenes linear. (Greek 

 rigios, stiff, and pappos, pappus.) 



1. R. leptocladus Gray. Three or 4 to 10 in. high, the herbage short-hairy 

 or nearly glabrous; branches filiform; heads 3 lines high; achenes hispidulous. 



Wooded hills: Antioch; North Coast Ranges; Tehama Co.; Sierra Nevada 

 foothills. June. 



42. CHAENACTIS DC. 



Ours annual with alternate pinnately parted or dissected leaves and yellow 

 flow irs. Heads peduncled, solitary or cymosely arranged. Bracts of the cam- 

 pa nulate involucre herbaceous, linear, equal, in one series. Receptacle flat, 

 naked. Corollas with short tube and long throat, or the marginal corollas in 

 some species with the limb palmately enlarged, forming a kind of ray. 

 Pappus of hyaline paleae, the paleae in the outer flowers commonly shorter 

 and fewer. (Greek chaino, to gape, and aktis, ray, in reference to the marginal 

 flowers of one section of the genus.) 



Paleae of the disk-flowers 4, equal 1. C. glabriuscula. 



Paleae of the disk-flowers 5, unequal 2. C. gracilcnta. 



1. C. glabriuscula DC. Five to 11 (or 19) in. high, thinly floccose, at 

 length glabrous; leaves pinnately parted into narrowly linear lobes or the 

 uppermost linear and merely toothed or entire; heads 5 to 7 lines high; 

 bracts of the involucre thickish; marginal corollas ample, much longer than 

 those of the disk; pappus-paleae 4, oblong-lanceolate, those of the disk equal, 

 of the marginal achenes with 1 long and 3 short ones; short paleae of the ray 

 relatively broader or even elliptical. 



Antioch; Sierra Nevada foothills; Coast Range foothills west of Red Bluff. 

 Apr. Var. lanosa Hall. Stems leafy only at the branching base, bearing many 

 long peduncles which are naked and scape-like; herbage whitish with floccose 

 wool which is later deciduous; leaves thickish, simply pinnate with few narrowly 

 linear and mostly short lobes or the upper entire; pappus-paleae 4, sometimes 

 5, equal or nearly equal, narrowly oblong or oblong-lanceolate, acutish. — Mon- 

 terey Co. and southward to Southern California; reported from the lower San 

 Joaquin. — (C. lanosa DC.) Var. heterocarpha Hall. Three-fourths to 1% 

 ft. high, with corymbose peduncles or often simple and 1-headed; herbage 

 hoary-tomentose but soon glabrous; Leaves pinnately or bipinnately parted, the 

 lobes short, unequal, crowded; heads <> lines high on long peduncles; marginal 

 corollas conspicuously enlarged, surpassing the disk; pappus of disk-achenes of 

 4 elliptic-oblong paleae equaling the corolla and of two or more roundish and 

 shorter outer ones; paleae of marginal flowers much shorter. — Lake Co.; upper 

 Sacramento Valley; Sierra Nevada. — (C. heterocarpha Gray.) 



2. C. gracilenta Greene. Simple below, corymbosely branching above, 7 

 or 8 in. high; Leaves 1 or 2 in. Long, with narrowly linear rarhis bearing oblong 

 lolics (1 Line Long) or short teeth; heads •"> or l lines high; marginal corollas 



little ampliate; achenes black, sparingly hispidulous with white hairs; pappus- 



