187m.19. Asteraceae Martinov (tribe Heliantheae) subtribe Hymenopappinae Rydberg in N. L. Britton et al., N. Amer. Fl. 34: 43. 1914.
Annuals, biennials, or perennials, (5–)20–150 cm. Leaves mostly basal or basal and cauline; alternate; petiolate or sessile; blades deltate to lanceolate overall, usually 1–2-pinnately or -palmati-pinnately lobed, lobes usually filiform, ultimate margins entire or toothed, faces glabrous or hairy, often tomentose, usually gland-dotted). Heads usually discoid, rarely radiate, usually in ± corymbiform arrays. Calyculi 0. Involucres obconic to hemispheric. Phyllaries persistent or tardily falling, 5–13+ in 2+ series (distinct, often yellowish, whitish, or purplish, orbiculate to lance-linear, subequal, often ± petaloid, margins usually notably membranous or scarious). Receptacles flat or convex, usually epaleate (paleae scarious, conduplicate, each ± investing subtended floret in H. newberryi). Ray florets usually 0, sometimes 8, pistillate, fertile; corollas white or whitish. Disc florets 12–70+, bisexual, fertile; corollas yellow or whitish to purplish, tubes longer than or about equaling funnelform or abruptly dilated, campanulate throats, lobes 5, ± deltate (reflexed at anthesis); anther thecae pale; stigmatic papillae in 2 lines. Cypselae obconic to obpyramidal, usually 4-angled and 12–16-ribbed, glabrous or hairy; pappi 0 or of 12–22 orbiculate to spatulate scales.
Genera 5, species 28 (1 genus, 10 species in the flora): North America, Mexico. H. Robinson (1981) suggested that Hymenopappinae is related to Gaillardiinae and other "core" groups of traditional Helenieae.