Mentzelia veatchiana |
Mentzelia pterosperma |
|
---|---|---|
Veatch's blazing star, white-stem blazingstar, white-stem stick-leaf |
wing-seed blazing star, wingseed stickleaf |
|
Habit | Plants candelabra-form, (5–)20–50 cm. | Plants winter annual or biennial, candelabra-form. |
Stems | solitary, erect, straight; branches distal, distal longest, antrorse, straight, hairy. |
|
Leaves | blade 13.8–78 × 3.8–20 mm, widest intersinus distance 2.5–15.8 mm; proximal oblanceolate to elliptic, margins entire or serrate to pinnate, teeth or lobes (0–)8–14(–22), slightly antrorse, 0.3–5.3 mm; distal elliptic to lanceolate, base usually clasping, rarely a few not clasping, margins usually serrate to pinnate, occasionally entire, teeth or lobes (0–)6–18, slightly antrorse, 2.8–4.3(–6.1) mm; abaxial surface with simple grappling-hook, occasionally complex grappling-hook, and rarely needlelike trichomes, adaxial surface occasionally with simple grappling-hook and needlelike trichomes. |
|
Basal leaves | persisting; petiole present or absent; blade linear-lanceolate, margins deeply to shallowly lobed. |
|
Cauline leaves | petiole absent; blade ovate-lanceolate 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. |
margins usually entire, rarely pinnate. |
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. |
petals golden yellow, 6.4–17(–20) × 2–5.3 mm, apex usually acute, occasionally rounded, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments linear to oblanceolate, slightly clawed, 6.2–14.2(–17.5) × 1–3.9 mm, usually without, rarely with, anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 6–11 mm. |
Capsules | clavate, 8–28 × 2–4 mm, axillary curved to 70° at maturity, usually inconspicuously longitudinally ribbed. |
cup-shaped, 7.3–13.7 × 5.5–9.8 mm, base rounded, not longitudinally ridged. |
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 10x 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. |
coat anticlinal cell walls straight, papillae 5–18 per cell. |
2n | = 54. |
= 22. |
Mentzelia veatchiana |
Mentzelia pterosperma |
|
Phenology | Flowering Mar–Jun. | Flowering Apr–Jun(–Jul). |
Habitat | Loamy to sandy soils, grasslands, desert scrub, oak-pine woodlands. | Disturbed soils, washes, sand dunes, roadcuts, badland knolls, clayey soils, gravelly soils with sandy or gypsum-rich clay. |
Elevation | 200–2500 m. [700–8200 ft.] | 300–1900 m. [1000–6200 ft.] |
Distribution |
AZ; CA; NV; OR
|
AZ; CA; CO; NV; UT
|
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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Mentzelia pterosperma occurs in the Colorado Plateau and Mojave Desert. Mojave Desert populations occur from eastern San Bernardino and southeastern Inyo counties, California, through Clark County, Nevada. Colorado Plateau populations are common in northern Arizona and extend northward to Utah and western Colorado. Populations in Utah occur in habitats composed of gravelly soils that are sandy or gypsum-rich clay, whereas Arizona and Nevada populations occur primarily on clayey soils, which sometimes contain gypsum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 543. | FNA vol. 12, p. 517. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | M. albicaulis var. veatchiana | |
Name authority | Kellogg: Proc. Calif. Acad. Sci. 2: 99, fig. 28. (1863) | Eastwood: Proc. Calif. Acad. Sci., ser. 2, 6: 290. (1896) |
Web links |