Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to Montana and Wyoming.
Habitat: Dry, often rocky or gravelly soil, desert valleys to lower mountains.
Flowers: July-September
Origin: Native
Growth Duration: Biennial, Perennial
Conservation Status: Not of concern
Pollination: Bumblebees, bees
Biennial or short-lived perennial from a deep taproot, the stem 3-10 dm. tall, single and branched, but often appearing multi-stemmed when branched near the base; harshly scabrid-pubescent.
Leaves alternate, the lower ones oblanceolate, with slender petioles, deeply pinnatifid, the lobes often angled backward, up to 15 cm. long; upper leaves sessile, oblong to ovate-oblong, more shallowly lobed.
Flowers solitary and terminal on branch ends and often in the upper leaf axils, each subtended by 1-several entire or few-toothed bracts; calyx lobes 5, linear, 1.5 -4 cm. long; petals 5, lemon yellow, 2.5-8 cm. long, narrowly oblong or oblong-lanceolate; stamens very numerous, 2/3 the length of the petals, the 5 outer ones without anthers, much widened and petaloid, alternate with the petals; style 1, stigma 3-4 mm., ovary inferior, 1-celled.
Capsule 1.5-3.5 cm. long.
PNW Herbaria: Specimen records of Mentzelia laevicaulis in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Mentzelia laevicaulis checklist entry
OregonFlora: Mentzelia laevicaulis information
E-Flora BC: Mentzelia laevicaulis atlas page
CalPhotos: Mentzelia laevicaulis photos