Mentzelia veatchiana

Plants candelabra-form, (5–) 20–50 cm. Basal leaves persisting; petiole present or absent; blade linear-lanceolate, margins deeply to shallowly lobed. Cauline leaves: petiole absent; blade ovatelanceolate to lanceolate, to 17 cm, margins usually deeply lobed to dentate, rarely entire. Bracts usually green with prominent white base usually conspicuously extending outwards from midvein, rarely green, usually ovate, rarely lanceolate, 3.3–6.2 × 1.5–3.2 mm, width 1/4–7/8 length, not concealing capsule, margins usually 3–7-lobed, rarely entire. Flowers: sepals 2–5 mm; petals red to orange proximally, orange to yellow distally, 4–7 (–10) mm, apex retuse; stamens 20+, 3–7 mm, filaments monomorphic, filiform, unlobed; styles (3–) 3.5–6 mm. Capsules clavate, 8–28 × 2–4 mm, axillary curved to 70° at maturity, usually inconspicuously longitudinally ribbed. Seeds 15–35, in 2+ rows distal to mid fruit, tan, dark-mottled, usually irregularly polygonal, occasionally triangular prisms proximal to mid fruit, surface tuberculate under 10× magnification; recurved flap over hilum absent; seed-coat cell outer periclinal wall domed, domes on seed edges more than or equal to 1/2 as tall as wide at maturity. 2n = 54.

Phenology: Flowering Mar–Jun.
Habitat: Loamy to sandy soils, grasslands, desert scrub, oak-pine woodlands.
Elevation: 200–2500 m.

Ariz., Calif., Nev., Oreg.

Discussion

Mentzelia veatchiana is the most common and widely distributed hexaploid species in sect. Trachyphytum. It exhibits considerable morphological variation and can be difficult to distinguish from M. montana in northern California. Like the larger-flowered M. pectinata, M. veatchiana has interfertile populations with petal colors ranging from orange to yellow (J. E. Zavortink 1966). When bearing orange petals, M. veatchiana is easily distinguished from other species. Reports of M. veatchiana from Utah are based on specimens treated here as M. montana.

Selected References

None.

Lower Taxa