276 COMPOSITE, (composite family.) 



49. RITDBECKIA, L. Cone-flower. 



Heads mauy-flowered, radiate; the rays neutral. Scales of the involucre 

 leaf-like, in about 2 rows, spreading. Receptacle conical or columnar; the 

 short chaff concave, not rigid. Achenes 4-angular (in our species), smooth, 

 not margined, flat at the top, with no pappus, or a minute crown-like border. 

 — Chiefly perennial herbs, with alternate leaves, and showy terminal heads ; 

 the rays generally long, yellow, often darker at base. (Named in honor of 

 the Professors Rudheck, father and son, predecessors of Linuceus at Upsal.) 



* Disk columnar in fruit, dull greenish-yellow ; leaves divided and cut. 



1. R. laciniata, L. Stem smooth, branching (2 - 7° high) ; leaves smooth 

 or roughish, the lowest pinnate, Avith 5-7 cut or 3-lobed leaflets; upper leaves 

 irregularly .3-5-parted, the lobes ovate-lanceolate, pointed, or the uppermost 

 undivided ; heads long-peduncled ; disk at first globular or hemispherical ; 

 chaff truncate, downy at the tip; rays oblanceolate (1 -2' long), drooping. — 

 LoAv thickets ; common. July - Sept. — Var. HtiMiLis, Gray, low and glabrous, 

 some of the radical leaves undivided or with roundish divisions ; heads smaller 

 {Y high) and ray shorter. Mountains of Va. and southward. 



* * Disk hemispherical to oblong-ovoid in fruit, dark purple or brown. 

 -t- Lower leaves 3-lobed or parted. 



2. R. triloba, L. Hairy, biennial, much branched (2-5° high), the 

 branches slender and spreading; upper leaves ovate-lanceolate, sj)aringly 

 toothed, the lower 3-lobed, tapering at the base, coarsely-serrate (those from 

 the root pinuately parted or undivided); rays 8, oval or oblong; chaff of the 

 black-purple depressed-globular disk smooth, awned. — Dry soil, Penn. to 

 Mich., Mo., and southward. Aug. — Heads small, but numerous and showy, 



3. R. SUbtomentosa, Pursh. Stem branching above (3-4° high), 

 downy, as well as the petiolate ovate or ovate-lanceolate serrate leaves beneath ; 

 heads short-peduncled ; disk globular, dull brown ; receptacle sweet-scented ; 

 chaff downy at the blunt apex. — Prairies, Wise, 111., Mo., and southward. 



-t- -«- Leaves undivided, rarehj laciniateli/ toothed. 



4. R. hirta, L. S«en«<'a/, very rough and bristly-hairy throughout; stems 

 simple or branched near the base, stout (1-2° high), naked above, bearing 

 single large heads ; leaves nearly entire ; the upper oblong or lanceolate, sessile ; 

 the lower spatulate, triple-nerved, petioled ; rays (about 14) more or less ex- 

 ceeding the involucre; chaff of the dull brown disk hairy at the tip, acutish. — 

 Dry soil, western N. Y. to Wise, and southward. Now common as a weed 

 in eastern meadows, introduced with clover-seed from the West. June- 

 Aug. 



5. R. flilgida, Ait. Hairy, the branches naked at the summit and bear- 

 ing single heads; leaves spatulate-oblong ov lanceolate, partly clasping, triple- 

 nerved, the upper entire, mostly obtuse; rays about 12, equalling or exceeding 

 the ample involucre; chaff of the dark purple disk nearly smooth and blunt. — 

 Dry soil, N. J. and Penn. to Ky., Mo., and southward. — Variable, 1-3° high ; 

 the rays orange-yellow. 



6. R. spathul^ta, Michx. Pubescence short and appressed ; slender, 

 8' -3° high; leaves obovate or spatulate or the upper ovate to lanceolate. 



