Syst. Bot. 27: 751, fig. 3. 2002.
Plants perennial, bushlike, with subterranean caudices. Stems multiple, erect or decumbent, straight; branches along entire stem, distal longest, antrorse, straight; hairy. Leaves: blade (13.5–)16.4–33.3 × 1.5–8.8 mm, widest intersinus distance 1.5–6.1 mm; proximal oblanceolate to spatulate, margins entire or pinnate, lobes 0–8 (always some leaves with 5+ lobes), perpendicular to leaf axis, 0.5–2 mm, always some more than 1.4 mm; distal oblanceolate, elliptic, lanceolate, or linear, base not clasping, margins entire, dentate, or pinnate, teeth or lobes 0–6, perpendicular to leaf axis, 0.1–2 mm; abaxial surface with complex grappling-hook, needlelike, and occasionally simple grappling-hook trichomes, adaxial surface with needlelike and generally simple grappling-hook trichomes. Bracts: margins entire. Flowers: petals golden yellow, 7.2–11.9 × 2.7–4.9 mm, apex acute to rounded, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 5.5–10.3 × 1.4–2.7 mm, with anthers, second whorl with anthers; anthers usually twisted after dehiscence, epidermis papillate; styles 5–9 mm. Capsules cup-shaped, 4.9–7.6 × 3.4–5.5 mm, base rounded to tapering, not longitudinally ridged. Seeds: coat anticlinal cell walls straight, papillae 5–8 per cell. 2n = 22.
Phenology: Flowering Jun–Aug.
Habitat: Sparsely vegetated cliffs and knolls, gypsum-rich clayey soils.
Elevation: 1400–1900 m.
Mentzelia argillicola is known only from Lincoln County.