Perennials, 10-50 cm; taprooted. Stems branched proximally and often distally. Leaves basal and cauline; petiolate (petioles broadly winged, clasping); blades linear to narrowly oblanceolate, 10-30 cm, margins entire, dentate, or pinnately lobed (lobes narrow, often retrorse). Peduncles erect (10-50 cm), ebracteate or leafy. Involucres narrowly ovoid in fruit, 8-17 mm. Phyllaries: sometimes purple-spotted, apices erect, acuminate, abaxial faces glabrous or scurfy-puberulent, often black-villous; outer lanceolate to deltate; inner lanceolate. Florets 8-30; corollas yellow, surpassing phyllaries by 5+ mm. Cypselae columnar, 4-7 mm; pappi of 5-10, white, lanceolate, glabrous, aristate scales 3-6 mm, aristae barbellulate. 2n = 18. Flowering May-Jun. Rocky serpentine soils, hillsides and alluvial flats, open shrublands and Pinus jeffreyi savannas; of conservation concern; 300-1000 m; Oreg. Microseris howellii is known only from exposures of peridotite in Josephine County, Oregon. Although related to M. laciniata, it is ecologically isolated from the co-occurring members of that complex. Because of its limited range, it is listed as a threatened taxon by the Oregon Natural Heritage Program (2004).