Cronquist’s blazingstar Cronquist’s blazingstar

Mentzelia marginata (Osterhout) H. J. Thompson & Prigge var. cronquistii (H. J. Thompson & Prigge) N. H. Holmgren & P. K. Holmgren; Nuttallia cronquistii (H. J. Thompson & Prigge) W. A. Weber

Plants biennial, candelabra-form. Stems solitary, erect, straight; branches distal or along entire stem, proximal longer than distal, all usually extending to near the distal end of plant, antrorse, straight; hairy. Leaves: blade 21–101 × 4–10.7(–19.3) mm, widest intersinus distance 1.8–7.3(–12.6) mm; proximal oblanceolate, lanceolate, or elliptic, margins dentate to pinnate, teeth or lobes 8–28, perpendicular to leaf axis, 1.2–6(–9) mm, always some more than 4 mm; distal oblanceolate, elliptic, or lanceolate, base not clasping, margins dentate to pinnate, teeth or lobes 6–18, perpendicular to leaf axis, 1.1–5(–6.9) mm; abaxial surface with simple grappling-hook, complex grappling-hook, and needlelike trichomes, adaxial surface with simple grappling-hook, needlelike, and occasionally complex grappling-hook trichomes. Bracts: margins entire or toothed to pinnate. Flowers: petals golden yellow, 9–16.6 × 2.5–5.1 mm, apex usually rounded, rarely acute, hairy abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 7.3–13.2 × 1.8–4.3 mm, usually without, rarely with anthers, second whorl with anthers; anthers straight after dehiscence, epidermis papillate or not; styles 6.5–10 mm. Capsules cup-shaped, 5.9–10.6(–11.4) × 5–7.6 mm, base tapering to rounded, not longitudinally ridged. Seeds: coat anticlinal cell walls wavy, papillae 8–13 per cell. 2n = 20.

Flowering May–Nov. Sandy and rocky soils, washes, roadside banks, steep slopes; 800–2300 m; Ariz., Colo., N.Mex., Utah.