Mentzelia veatchiana |
Mentzelia desertorum |
|
---|---|---|
Veatch's blazing star, white-stem blazingstar, white-stem stick-leaf |
desert blazing star |
|
Habit | Plants candelabra-form, (5–)20–50 cm. | Plants candelabra-form, 5–40 cm. |
Basal leaves | persisting; petiole present or absent; blade linear-lanceolate, margins deeply to shallowly lobed. |
persisting; petiole present or absent; blade linear, margins usually shallowly lobed, lobes rounded. |
Cauline leaves | petiole absent; blade ovate-lanceolate to lanceolate, to 17 cm, margins usually deeply lobed to dentate, rarely entire. |
petiole absent; blade ovate-lanceolate to linear, to 12 cm, margins shallowly lobed or 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. |
green, ovate to ovate-lanceolate, 3.6–4.7 × 1.6–2.3 mm, width 1/3–1/2 length, not concealing capsule, margins 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. |
sepals 2–4 mm; petals yellow to orange proximally, yellow distally, 2–6 mm, apex acute or rounded; stamens 10–30, 2–4 mm, filaments monomorphic, filiform, unlobed; styles 2–4 mm. |
Capsules | clavate, 8–28 × 2–4 mm, axillary curved to 70° at maturity, usually inconspicuously longitudinally ribbed. |
clavate, 12–27 × 1–2.5 mm, axillary curved to 180° 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 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. |
10–50, in 2+ rows distal to mid fruit, tan, usually not, occasionally sparsely, dark-mottled, usually irregularly polygonal, occasionally triangular prisms proximal to mid fruit, surface tessellate under 10x magnification; recurved flap over hilum absent; seed coat cell outer periclinal wall flat to slightly convex. |
2n | = 54. |
= 18. |
Mentzelia veatchiana |
Mentzelia desertorum |
|
Phenology | Flowering Mar–Jun. | Flowering Feb–Mar. |
Habitat | Loamy to sandy soils, grasslands, desert scrub, oak-pine woodlands. | Sandy flats, washes, creosote-bush scrub. |
Elevation | 200–2500 m. [700–8200 ft.] | 30–1000 m. [100–3300 ft.] |
Distribution |
AZ; CA; NV; OR
|
AZ; CA; Mexico (Baja California, Sonora) |
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 desertorum, a diploid, is most similar morphologically to the tetraploid M. obscura, and the two species may be difficult to distinguish prior to seed maturation. However, many populations of M. desertorum have narrow basal leaves with short, widely spaced lobes that are unique among species within sect. Trachyphytum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 543. | FNA vol. 12, p. 536. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | M. albicaulis var. veatchiana | Acrolasia desertorum |
Name authority | Kellogg: Proc. Calif. Acad. Sci. 2: 99, fig. 28. (1863) | (Davidson) H. J. Thompson & J. E. Roberts: Phytologia 21: 280. (1971) |
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