SUNFLOWER FAMILY. 4f)3 



60. HELIANTHELLA T. & G. 



Low nearly acaulescent perennial herbs. Leaves entire, chiefly radical, the 

 redueed cauline mostly opposite. Flowers yellow. Heads large, solitary, long- 

 peduncled. [nvolucre hemispherical, its bracts linear-lanceolate and loosely im- 

 bricate. 1, the outer mostly foliaeeous and attenuate-acuminate, the innermost 

 shorter and chart-like. Receptacle flat or convex, its bracts embracing the 

 achenes. Achenes commonly compressed, with thin or margined edges and 

 emarginate summit. Pappus an awn or chaffy tooth from each margin, and 

 usually with very small intermediate scales. (Diminutive of Helianthus.) 



1. H. calif ornica Gray. Stems slender, 1 to 2 ft. high, occasionally 

 branched; herbage minutely scabrous; leaves ovate to oblong-lanceolate, 

 tapering into petioles; rays % to 1 in. long, usually little longer than the 

 involucre; bracts of receptacle obtuse; achenes obovate, smooth, glabrous 

 and narrowly margined, minutely ciliate when young only near the summit; 

 pappus of two teeth and a crown of minute scales, the whole sometimes obso- 

 lete at maturity. 



Higher mountain ridges: Coast Ranges (Contra Costa, Marin, Napa and 

 Solano cos. and northward to Mt. Shasta) ; Sierra Nevada. May. 



61. BIDENS L. Bur Marigold. 



Herbs (ours annual), with opposite leaves and yellow flowers. Heads many- 

 flowered; rays 3 to 9, neutral. Involucre double, the outer bracts linear-oblong, 

 foliaeeous, the inner elliptic to ovate, membranous. Achenes somewhat 

 flattened parallel with the scales of the involucre or slender and 4-sided, those 

 of the disk crowned with 2, 3, or 4 rigid persistent retrorsely barbed awns. 

 (Latin bidens, 2-toothed.) 



Leaves simple; rays 3 to 9, conspicuous; achenes downwardly barbed on the margin; rays 

 showy. 

 Outer involucre little or not at all surpassing the disk; rays very showy, golden yellow.. 



1. B. chrysanthemoid.es. 

 Outer involucre foliaeeous and surpassing the disk; rays usually light yellow, smaller... 



2. B. cernua. 

 Leaves pinnately 3 to 5-divided; rays 1 to 5, inconspicuous; achenes upwardly barbed.... 



3. B. frondosa. 



1. B. chrysanthemoides Michx. Bur Marigold. Often decumbent at base, 

 1 to 3 or even 4 ft. high, glabrous; leaves lanceolate, usually tapering at the 

 base, evenly serrate, more or less connate at base, 7 in. long or less; outer 

 involucre rather longer than the inner, much surpassed by the oval golden 

 brown rays, these 1 in. long or more ; disk brownish ; heads in fruit erect, 

 seldom slightly nodding; achenes flat or flattish, cuneate, distinctly carinate on 

 the sides and retrorsely hispid on the marginal angles; awns 2 or 3, retrorsely 

 barbed. 



Low wet ground: Alvarado marshes; lower Sacramento River. Sept. -Oct. 

 Var. xashii Jepson. Leaves minutely serrate or almost entire, somewhat 

 fleshy, some of the upper often very broad at base but rarely clasping; achenes 

 slightly contracted at summit. — San Francisco, ace. to Wiegand. 



2. B. cernua L. Smaller Bur Marigold. Stems 8 to 20 in. high, glabrous 

 or setulose-hispid ; leaves oblong-lanceolate, rather irregularly serrate, mostly 

 not connate; outer involucral bracts exceeding the disk, spreading, foliaeeous; 

 rays 6 to 10, mostly light yellow, 3 to 6 lines long, sometimes none; heads 

 strongly nodding in fruit ; achenes 4-angled and usually 4-awned. 



Less common than the last. 



3. B. frondosa L. Bewar-ticks. Erect, 3 or 4 ft. high, glabrous or slight- 

 ly pubescent; leaves 3 to 5-divided, the divisions or leaflets petiolulate, lance- 



