Perennials, 15-120 cm; taprooted. Stems branched and leafy distally, or simple and leafy only proximally (subsp. detlingii and plants of extreme environments). Leaves basal and cauline; petiolate (distal often sessile, clasping); blades linear to broadly lanceolate, 10-50 cm, margins entire, dentate, lacerate, or pinnatifid, apices obtuse to acuminate, faces glabrous or scurfy-puberulent. Peduncles erect or curved-ascending, ebracteate or leafy (10-70 cm). Involucres globose to narrowly ovoid in fruit, 10-30 mm. Phyllaries: often purple-spotted (especially in subsp. laciniata), apices erect. abaxial faces glabrous or scurfy-puberulent (often black-villous in subsp. leptosepala); outer lanceolate to broadly ovate, deltate, or linear, slightly to much shorter than inner, 0.5-9 mm wide. apices cuspidate to acute; inner broadly to narrowly lanceolate, apices acuminate. Florets 13-300; corollas yellow, surpassing phyllaries by 5+ mm. Cypselae columnar, 3.5-8 mm (tapering to bases); pappi of 5-10(-15 in subsp. detlingii, or -24 in subsp. siskiyouensis), white to dull yellowish, deltate to lanceolate, aristate scales 0.5-8 mm, aristae barbellulate to barbellate. 2n = 18.

Microseris laciniata comprises four, mostly allopatric subspecies, the diagnostic features of which are found mainly in the phyllaries and pappi. These races intergrade where they come in contact, with the greatest diversity occurring in the Klamath Mountains of northern California and southern Oregon (K. L. Chambers 2004b). S. Mauthe et al. (1981) reported on a detailed morphologic analysis of the heads and pappi of M. laciniata and proposed that the observed variation could be explained by the interaction of a limited number of major genes. The species is consistently self-sterile and outcrossing. It also may reproduce clonally by adventitious buds borne on lateral roots.