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FNA | Family List | FNA Vol. 21 | Asteraceae

371. Hymenothrix A. Gray, Mem. Amer. Acad. Arts, n. s. 4: 102. 1849.

[Greek hymen, membrane, and thrix, hair, possibly alluding to scarious-aristate pappus scales]

John L. Strother

Annuals, biennials, or perennials, 10–70[–150] cm. Stems erect, branched. Leaves basal and cauline; mostly alternate (proximal opposite); petiolate; blades 2-ternately [pinnately] lobed, ultimate margins entire, faces usually ± scabrellous (hairs white, antrorse, 0.1–0.5 mm), sometimes glabrate, sometimes gland-dotted. Heads radiate or discoid, in corymbiform to paniculiform arrays. Involucres obconic to hemispheric, 4–8+ mm diam. Phyllaries persistent, 8–16 in 2–3 series (reflexed in fruit, obovate or oblanceolate to linear, subequal, sometimes subtended by 1–3 bractlets, thin-herbaceous to membranous, margins scarious, often tinged with purple). Receptacles flat or convex, knobby or smooth, epaleate. Ray florets 0, or 3–8+, pistillate, fertile; corollas yellowish. Disc florets 10–30+, bisexual, fertile; corollas yellowish or whitish or pinkish to purplish (sparsely glandular-hairy), tubes about equaling cylindric throats or much longer than broadly funnelform throats, lobes 5, lance-oblong or lance-linear. Cypselae obpyramidal, 4–5-angled, faces ribbed and sparsely hairy (hairs straight); pappi persistent, of 12–18 narrowly lanceolate to subulate, medially thickened, scarious-margined scales in 1 series, some or all ± aristate. x = 12.

Species 5 (3 in the flora): sw United States, Mexico.


Turner, B. L. 1962. Taxonomy of Hymenothrix (Helenieae, Compositae). Brittonia 14: 101–120.

1 Phyllaries (8–)12–16, mostly oblong to ovate or obovate; corollas white or pinkish to purplish, lobe lengths 2–3+ times throats; anthers pinkish to purplish   3 Hymenothrix wrightii
+ Phyllaries 8(–12), mostly linear to narrowly oblanceolate; corollas creamy to bright yellow, lobe lengths 0.3–1 times throats; anthers yellowish   (2)
2 (1) Rays 3–8; corollas of disc florets mostly 5–7 mm   1 Hymenothrix wislizeni
+ Rays 0; corollas of disc florets mostly 4–4.5 mm   2 Hymenothrix loomisii

Lower Taxa


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