General:
Annual herb from a taproot: stems erect to ascending or decumbent, simple, solitary to several, leafless, exuding milky juice when broken, 4-35 cm tall.

Leaves:
Basal leaves linear to oblanceolate or spoon-shaped, entire or coarsely pinnately cut with slender or broad tapering lobes or teeth, glabrous, 3-25 cm long; stem leaves lacking.

Flowers:
Heads with strap-shaped flowers, solitary at end of stems, nodding until mature; involucres 6-15 mm tall; involucral bracts broadly lanceolate, the inner ones keeled, often reddish on the outer surface, long black-hairy within, the outer ones short and bractlike; ray flowers yellow or yellow-orange.

Fruits:
Achenes tapered abruptly at the base, brown or bronze, sometimes darkly spotted, 2.5-6 mm long; pappus of 5 glabrous or short-hairy, lanceolate scales, each terminating in a long, hairlike bristle arising from the pointed scale.

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.