Biennials (sometimes winter annuals) [perennials], (15-)50-150 cm; taprooted. Stems 1(-5), erect, usually branched proximally, glabrous or tomentulose to floccose [lanate], often glabrescent. Leaves basal and cauline; sessile; blades linear to lance-linear or lance-attenuate (grasslike) [lanceolate to oblong], (bases clasping) margins entire (faces glabrous or tomentulose to floccose [lanate], often glabrescent). Heads borne singly (terminal). Peduncles often inflated distally (not in T. pratensis), ebracteate. Calyculi 0. Involucres campanulate [cylindric] (at flowering), mostly 10-20+ mm diam. Phyllaries usually [5-7] 8-12 [13-16] in 1 series, linear-lanceolate, triangular-lanceolate [oblong-lanceolate], linear, ± equal, margins white, narrowly pellucid, apices acute (faces glabrous [with intertwining hairs]). Receptacles convex, smooth, glabrous, epaleate. Florets (30-)50-180+; corollas yellow or purple (proximally yellow, distally purple in T. mirus) (± deliquescent). Cypselae dark to pale brown, stramineous, whitish, bodies ± fusiform to cylindric, usually beaked, beaks concolorous with, or paler than bodies, abrupt to gradually tapered, 5-10-ribbed (ribs usually muricate, prickly, or scaly), faces usually glabrous, sometimes scaley or muricate; pappi (usually borne on discs at tips of beaks) persistent, of 12-20+, brownish to whitish, basally connate, ± plumose, subequal to unequal awns or subulate scales, in 1 series (lateral barbs or setulae often ± intertwined). x = 6. Tragopogon is weedy in North America. Allotetraploids T. mirus and T. miscellus are native to the United States. The heads of tragopogons usually open early mornings and close by midday.
Fls all ligulate and perfect, yellow or purple; invol cylindric or campanulate, its bracts uniseriate and equal; receptacle naked; achenes linear, terete or angled, 5-10-nerved, narrowed at base, slender-beaked, or the outer occasionally beakless; pappus a single series of plumose bristles, united at base, the plume- branches interwebbed, several of the bristles commonly longer than the others and naked at the tip; taprooted lactiferous herbs with alternate, linear, entire, clasping, commonly somewhat grass-like lvs, the heads solitary at the ends of the branches. 50, mainly Eurasia and n. Afr.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.