Prenanthella exigua

Flora of Oregon

Herbs annual, 5–30 cm, sap milky; taproots slender.

Stems erect, proximally leafy, glabrous or minutely glandular-pubescent, branched near bases or distally.

Leaves basal and cauline, blades broadly to narrowly oblanceolate, 0.5–3 cm, reduced distally to bracts, margins irregularly dentate to lobed, surfaces glabrous, teeth spine-tipped.

Inflorescences panicle-like arrays, much branched; peduncles bracteolate.

Heads 10–150+, ligulate.

Involucres ovoid.

Phyllaries 3–5, in 1 series, lanceolate, tips acute, surfaces glabrous or minutely glandular.

Receptacles flat to ± convex, smooth, glabrous; paleae 0.

Florets 3–4, bisexual; ligules 1.5–2 mm, slightly exceeding involucres, pink or white.

Fruits columnar, tapering downward, 2.5–3.5 mm, pale brown, glabrous, 5-ribbed and grooved, ribs minutely roughened; pappi of basally joined, smooth, white bristles in 2 unequal series, longest bristles 2–3 mm.

2n=14.

Sandy, gravelly, or clay soils, desert washes and slopes, sagebrush-juniper steppe. Flowering Mar–Jun. 800–1100 m. Owy. CA, NV; southeast to TX, south to Mexico. Native.

Flora of North America

as described under Prenanthella exigua

Leaves 1-3 cm, reduced distally to bracts 0.5-5 mm. Heads 10-150+. Calyculus bractlets 0.5-1+ mm. Principal phyllaries 3-5 mm after flowering. Corollas 1.5-2 mm. Cypselae 2.5-3.5 mm; pappi: longest bristles 2-3 mm. 2n = 14.Flowering Mar-Jun. Sandy, gravelly, or clay soils, desert washes and open slopes to sagebrush-juniper steppes; 20-1900 m; Ariz., Calif., Colo., Nev., Oreg., Tex., Utah; Mexico (Baja California, Sonora).

Herbarium specimens

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