Hymenoxys richardsonii
Bull. Torrey Bot. Club 31: 468. 1904.
Perennials, 7–34 cm (polycarpic; usually with highly branched woody caudices). Stems 1–20 (–30+), usually green throughout, rarely purple-red-tinted proximally, branched distally, glabrous or ± hairy. Leaves: blades simple or lobed (lobes 3–7), glabrous or ± hairy, glanddotted (basal leaf-bases densely long-villous-woolly); mid leaves lobed (lobes 3–5, terminal lobes 0.7–2 mm wide). Heads 5–300+ per plant, in corymbiform arrays. Peduncles 1–5 cm, ± hairy. Involucres campanulate, 7–11 × 7–14 mm. Phyllaries in 2 series, unequal; outer 8–13, obovate to ovate to lanceolate, basally connate 1/2 their lengths, 3.5–8 mm, apices acuminate to acute; inner 8–18, obovate, 3–8 mm, apices mucronate. Ray-florets 7–14; corollas yellow, 7–17 × 3–6 mm. Disc-florets 25–75+; corollas 3–5 mm. Cypselae narrowly obpyramidal, 2–3 mm; pappi of 4–8 obovate to lanceolate, aristate scales 1.8–3.5 mm. 2n = 30.
Distribution
Alta., Sask., Ariz., Colo., Mont., N.Dak., N.Mex., Tex., Utah, Wyo.
Discussion
Varieties 2 (2 in the flora).
Selected References
None.
Key
| 1 | Stems 1–10; leaves ± hairy; heads 5–35+ per plant; involucres 8–11 × 9–14 mm; outer phyllaries 9–13, weakly to moderately keeled; ray corollas 11–17 mm | Hymenoxys richardsonii var. richardsonii |
| 1 | Stems (2–)5–20(–30+); leaves glabrous or sparsely hairy; heads (30–)80–250(–300+) per plant; involucres 7–8 × 7–9 mm; outer phyllaries 8–9, strongly keeled; ray corollas 7–11 mm | Hymenoxys richardsonii var. floribunda |