Mentzelia hualapaiensis

Plants perennial, bushlike, with subterranean caudices. Stems multiple, erect, zigzag or straight; branches distal or along entire stem, distal longest or all ± equal, antrorse, upcurved; hairy. Leaves: blade 17–94 × 12–32 mm, widest intersinus distance 9.5–29 mm; proximal broadly spatulate to elliptic, margins serrate, teeth 6–12, slightly antrorse or perpendicular to leaf axis, 0.4–1.5 mm; distal broadly spatulate, elliptic, or obovate, base not clasping, margins serrate, teeth 8–10, slightly antrorse or perpendicular to leaf axis, 1–3.6 mm; abaxial surface with complex grappling-hook and occasionally with simple grappling-hook and needlelike trichomes, adaxial surface with needlelike trichomes. Bracts: margins entire. Flowers: petals white to light yellow, 9.4–17.4 (–20) × 1.7–4.3 mm, apex acute to rounded, glabrous abaxially; stamens white to light yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 8.5–18 × 1–1.3 (–2.9) mm, without anthers, second whorl with anthers; anthers straight after dehiscence, epidermis papillate; styles 5.8–9 mm. Capsules cupshaped, 4.9–10.3 × 4.6–8.6 mm, base rounded, not longitudinally ridged. Seeds: coat anticlinal cell-walls straight to slightly wavy, papillae 8–14 per cell.

Phenology: Flowering Mar–Jun(–Sep).
Habitat: Rocky desert scrub, gravelly canyon bottoms, steep travertine, shaley slopes associated with Muav limestone formations.
Elevation: 400–1400 m.

Ariz.

Discussion

Mentzelia hualapaiensis is distributed in Coconino and Mohave counties along the Grand Canyon and its side canyons between the Upper and Lower Granite Gorge.

Selected References

None.

Lower Taxa