6. Microseris howellii A. Gray, Proc. Amer. Acad. Arts. 20: 300. 1885.
Scorzonella howellii (A. Gray) Greene
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).