228. Lagascea Cavanilles, Anales Ci. Nat. 6: 331. 1803.
单花葵属 dan hua kui shu
Annual herbs or perennial shrubs. Stems terete, glabrous to pilose and often stipitate glandular. Leaves opposite, petiolate or sessile; blade ovate to oblanceolate, subglabrous to sericeous abaxially, subglabrous to strigose adaxially, base obtuse to subauriculate, margin obscurely to markedly serrate, apex acute to acuminate. Synflorescence globose to campanulate, of 1-flowered (rarely 2- or 3-flowered) capitula aggregated secondarily, sometimes to third degree, solitary, cymose, or racemose clusters; receptacle convex; secondary phyllaries separate, herbaceous, lanceolate to obovate, abaxially subglabrous to pilose and sometimes stipitate glandular; primary phyllaries laterally connate into an involucral tube, abaxially subglabrous to densely pilose, with 1-3 rows of resinous glands, apices acute to acuminate and sometimes stipitate glandular. Florets bisexual; corollas yellow, white, pink, or red, narrowly funnelform, lobes 5; anthers yellow, tan, brown, black, pink, or red; style bifid, style branches tapering toward apices. Achenes brown to black, narrowly cylindric to obovoid, minutely grooved, glabrous or setuliferous; pappus an erose pubescent crown or of short pubescent awns.
About nine species: mainly in Mexico and Central America, one species is a widespread pantropic weed; one species (introduced) in China.
See Stuessy, Fieldiana, Bot. 38(8): 75-133. 1978.