254. Chorisiva (A. Gray) Rydberg in N. L. Britton et al., N. Amer. Fl. 33: 8. 1922.
[Greek choris-, separate, and Iva, a related genus; allusion recondite, perhaps "separate from Iva" or to "scattered" arrangement of heads]
John L. Strother
Iva Linnaeus sect. Chorisiva A. Gray in A. Gray et al., Syn. Fl. N. Amer. 1(2): 247. 1884
Annuals, 5–25(–40) cm. Stems erect, diffusely branched. Leaves cauline; mostly alternate; petiolate; blades ovate or deltate to lanceolate, usually 1–2-pinnately lobed (lobes lance-ovate to linear), ultimate margins entire or toothed, faces ± scabrellous, usually gland-dotted. Heads ± discoid, mostly borne singly (in leaf axils or remote from axils, ± scattered). Involucres ± turbinate to campanulate, 2–3+ mm diam. Phyllaries persistent, 3–8+ in 1–2+ series, distinct, outer 3+ herbaceous, inner scarious to membranous, glabrous. Receptacles convex; paleae linear to setiform, membranous, usually with dilated, strigillose or ciliate tips. Pistillate florets 2–3(–5); corollas yellowish, tubular. Functionally staminate florets 5–10+; corollas yellowish, funnelform, strigillose and gland-dotted distally, lobes 5, erect (filaments ± connate, anthers weakly coherent or distinct). Cypselae obovoid, obcompressed, smooth or corky-tuberculate, glabrous (not corky-winged, not gland-dotted); pappi 0.
Species 1: sw United States.
