150 FAM. 173. 



P. uvedalia. Leaves broadly ovate, 3-5 lobed, contracted into a short petiole 



ray-flowers 10-14, longer than the involucre, bright yellow. Damp soil. 



Summer. 



i 



28. Heads inconspicuous; achenes short and thick, not flattened; — 



coarse pubescent herbs with opposite, often leathery leaves; 

 heads in the axils of leaf-like bracts; involucre double, 5 outer 

 bracts herbaceous and several small inner bracts which form a 

 burr around the achene; receptacle concave or convex; ray-flowers 

 few, yellowish; pappus absent. ----- Acanthospermum 



A. australe (xanthioides). Prostrate; leaves ovate to rhombic, serrate-dentate, 



on short peduncles; bracts prickly. Dry soil. Spring to Fall. 



29. Leaves opposite; heads few, peduncled; pappus a cup-shaped crown; 



— low, pubescent or hirsute herbs with broad, petioled leaves; 

 involucre double, consisting of 5 leafy outer, and as many firm 

 inner bracts as there are rays; disk-flowers each with a bractlet; 

 achenes flat, each adnate to its bract. _ _ _ Chrysogonum 



C. Virginian um. Plant stoloniferous; leaves oblong to oval, serrate or crenate, 

 at first radical; heads few or single; with about 5 light- yellow rays. Flat- 

 woods. Spring. 



29. Leaves alternate or basal; heads solitary or corymbose; pappus ob- 



solete or of 2 caducous awns; — herbs with the leaves toothed or 

 pinnatifid; bracts of the involucre in about 3 rows, and recep- 

 tacle chaffy; ray-flowers 5-12, yellow. - _ _ _ Berlandiera 



B. pumila (tomentosa). Simple or sparingly branched, grayish -tomentose; 



leaves oblong to oval, crenate; achenes ciliate. Sandy soil. Summer and 

 Fall. 



B. humilis. Acaulescent, tomentose; leaves oblong to ovate, crenate or pin- 

 natifid near the base; scapes simple or corymbose above; achenes woolly. 

 Pine-land. Spring to Fall. 



B. subacaulis. Tufted, hispidulous; leaves chiefly basal, sinuate or lyrate pin- 

 natifid, oblong or oblanceolate; achenes somewhat ciliate. Sand. Spring to 

 Fall. 



30. Receptacle fimbrillate to naked; — herbs with alternate or basal 



leaves, entire, toothed or pinnatifid; heads long-peduncled; 

 bracts of involucre in 2-3 rows, broad, at least the outer row 

 spreading; receptacle convex; rays mostly neutral, yellow or 

 purple or both; disk-flowers perfect and fertile; pappus of 6-12 

 awns which are membranous at the base. Spring to Fall. - Gaillardia 



G. lanceolata. Brownish-pubescent, loosely branched; leaves spatulate to lin- 

 ear, mostly sessile; rays yellow, disk purple; receptacle almost naked. Sandy 

 pine-land. 



G. pulchella, var, picta, with comspicuous ligules; receptacle firmbrillate. Cul- 

 tivated. 



30. Receptacle chaffy throughout, - - - - - - - - 31 



31. Involucre simple or imbricated, -____--- 32 



31. Involucre double; pappus 2 or 4 awned, ------ 33 



32. Pappus a cup-shaped border, or 2-4 short teeth, or absent; — herbs 



with alternate, toothed or pinnatifid leaves; heads showy, ter- 

 minating the stem or branches; involucre imbricated, bracts in 

 2-more rows; disk-flowers perfect and fertile. - Rudbeckia, Cone-flower 



R. laciniata. Stems smooth, usually branched; leaves from pinnately 3-7 fol- 

 iate below, to toothed or entire at the top of the stem, petioled or sessile; 



