Mentzelia rhizomata

Roan Cliffs blazingstar Roan Cliffs blazingstar

Nuttallia rhizomata (Reveal) W. A. Weber & R. C. Wittmann

Plants perennial, bushlike, with rhizomes. Stems multiple, erect or decumbent, zigzag; branches along entire stem, distal longest, antrorse, upcurved; hairy. Leaves: blade 8.1–29 × 4.1–12.7 mm, widest intersinus distance 4.1–7.4 mm; proximal oblanceolate, margins entire; distal elliptic, base not clasping, margins entire or dentate, teeth 0–8, perpendicular to leaf axis, 0.6–2.7 mm; abaxial surface with simple grappling-hook and needlelike trichomes, adaxial surface with needlelike trichomes. Bracts: margins entire. Flowers: petals golden yellow, 12.5–17.2 × 6.1–11.2 mm, apex rounded to obtuse, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, strongly clawed, 7–9.5 × 2.7–6 mm, with anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 7–10 mm. Capsules cup-shaped, 7–10 × 6.5–8 mm, base rounded, not longitudinally ridged. Seeds: coat anticlinal cell walls straight, papillae 9–13 per cell.

Flowering Jul–Aug. Sparsely vegetated, steep talus slopes with loose gravelly soils; of conservation concern; 1700–2100 m; Colo.

Mentzelia rhizomata is known only from Garfield County.