Plants 2-6 cm. Stems simple or branched, rarely with many branches from bases. Leaf blades linear to filiform, 12-32 × 0.5-1 mm. Involucres turbinate to campanulate. Phyllaries in 2(-3) series, elliptic to obovate, glabrous or sparsely and minutely glandular. Ray (or pistillate) florets 0 or 1-5; corollas white, laminae 0.8-2 mm, or 0, or apiculum 0.1-0.5(-1) mm. Disc florets 3-6(-15); corollas yellowish to reddish, club-shaped, widened through limbs, abruptly contracted at lobes, lobes 5, (lobes and sometimes distalmost portion of limbs) yellow or purplish red at maturity, style branches (0.7-)1-2 mm, stigmatic portions 0.4-0.5 mm. P appi 0, or of (3-)5 bristles, not dilated at bases. 2n = 18.

Plants of Pentachaeta exilis with greatly reduced or completely absent pappi apparently are scattered over the range of the species. This feature is relatively constant within a population.