Flora of Oregon

Herbs annual or perennial, sap milky; taprooted.

Stems erect, leafless except for scaly bracteoles in inflorescences, branched, glabrous or proximally rough-hairy.

Leaves basal, oblanceolate, bases tapering and petiole-like, margins irregularly dentate or lobed, tips acute or obtuse, surfaces glabrous or rough-hairy.

Inflorescences terminal, branched, with solitary heads; bracteate.

Heads ligulate.

Involucres narrowly to broadly campanulate in flower, cylindrical to ovoid in fruit.

Phyllaries 10–30 in 4–5 graduated series, erect, reflexed in fruit, surfaces glabrous or midribs with stiff, sharp hairs.

Receptacles flat to convex; paleae membranous.

Florets bisexual; ligules slightly to much exceeding involucres, white or yellow.

Fruits tapering toward bases and tips or only toward bases, brown, finely roughened, glabrous, ribs 10+; pappi of stiff, plumose bristles, tawny or dull white, shorter outer bristles barbed.

Africa, Asia, Europe, North America, South America. 50–100 species; 2 species treated in Flora.

Flora of North America

as described under Hypochaeris

Annuals, biennials, or perennials, 10-60 cm; taprooted and with caudices. Stems 1-15, erect, branched or unbranched, glabrate or coarsely hirsute. Leaves basal or basal and proximally cauline; petiolate or sessile; blades oblanceolate to oblong or elliptic, margins entire or dentate to pinnately lobed (faces glabrous or hirsute). Heads borne singly or in loose, cymiform, paniculiform. or corymbiform arrays. Peduncles slightly inflated distally, minutely bracteate. Calyculi 0 (or indistinguishable from phyllaries) . Involucres cylindric or campanulate, 5-20 mm diam. (12-25 mm in fruit). Phyllaries 20-30 in 3-4 series, unequal. linear-lanceolate, glabrous, glabrate, or coarsely hirsute. Receptacles flat, slightly pitted, paleate; paleae linear to subulate, scarious. Florets 20-100+; corollas usually yellow or orange, sometimes grayish green or reddish abaxially, rarely white, (not deliquescent). Cypselae monomorphic (all beaked) or dimorphic (outer truncate, inner beaked), usually brown to golden, bodies ellipsoid or fusiform, ribs 4-5 or 10. faces ± muricate, otherwise glabrous; pappi persistent, of 40-60+, white to tan bristles in 1 (all plumose) or in 2 series (outer barbellate, shorter than plumose inner). x = 4, 5.Hypochaeris is similar to and closely related to Leontodon, from which it is distinguished mainly by its paleate receptacles and unequal phyllaries. Plumose pappus bristles are characteristic of both Hypochaeris and Leontodon. Molecular studies indicate the South American species of Hypochaeris are a monophyletic group derived from European stock that has undergone a recent and rapid radiation in the New World (R. Samuel et al. 2003). Two South American species are found as weeds in the flora area.

Species, subspecies and varieties