Mentzelia veatchiana |
Mentzelia albicaulis |
|
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Veatch's blazing star, white-stem blazingstar, white-stem stick-leaf |
small flower blazing star, small-flower evening star, white stem blazing star, white-stem evening star, white-stem stick-leaf |
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Habit | Plants candelabra-form, (5–)20–50 cm. | Plants wandlike or candelabra-form, (2–)10–40(–50) cm. |
Basal leaves | persisting; petiole present or absent; blade linear-lanceolate, margins deeply to shallowly lobed. |
persisting; petiole present or absent; blade linear-lanceolate to linear, 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. |
petiole absent; blade ovate-lanceolate to linear, to 15 cm, margins deeply to 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 linear, 3.7–8.6 × 0.8–3.9 mm, width 1/6–2/3 length, not concealing capsule, margins 3-lobed or entire, lateral lobes never prominent. |
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 1–5 mm; petals orange proximally, yellow distally, 3–7(–8) mm, apex usually acute, rarely retuse; stamens 20+, 3–5 mm, filaments monomorphic, filiform, unlobed; styles 2–5 mm. |
Capsules | clavate, 8–28 × 2–4 mm, axillary curved to 70° at maturity, usually inconspicuously longitudinally ribbed. |
clavate, 8–28(–35) × 1.5–3.5 mm, longest capsules usually 15+ 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. |
10–30, in 2+ rows distal to mid fruit, dark brown or tan, moderately to densely 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 1/2 as tall as wide at maturity. |
2n | = 54. |
= 54, 72. |
Mentzelia veatchiana |
Mentzelia albicaulis |
|
Phenology | Flowering Mar–Jun. | Flowering Mar–Aug. |
Habitat | Loamy to sandy soils, grasslands, desert scrub, oak-pine woodlands. | Sand dunes, gravel fans, washes, desert scrub, sagebrush or antelope bitterbrush scrub, open ponderosa pine woodlands, pinyon/juniper woodlands. |
Elevation | 200–2500 m. [700–8200 ft.] | 0–2300 m. [0–7500 ft.] |
Distribution |
AZ; CA; NV; OR
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AZ; CA; CO; ID; MT; NE; NM; NV; OR; SD; TX; UT; WA; WY; BC; SK; Mexico (Baja California, Chihuahua, Sonora)
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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 albicaulis is the most widespread species in sect. Trachyphytum and exhibits extensive morphological variation. Most populations of M. albicaulis are octoploid; however, hexaploids from southern California that have been called M. mojavensis and occasionally M. californica are also treated here as M. albicaulis. Two tetraploids in sect. Trachyphytum, M. montana and M. obscura, also have been treated previously as M. albicaulis (N. H. Holmgren et al. 2005). Both exhibit morphological forms and distributions overlapping with M. albicaulis. However, in most cases these species can be distinguished without chromosome counts, and their distinctiveness has been supported by phylogenetic analyses (J. M. Brokaw and L. Hufford 2010b). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 543. | FNA vol. 12, p. 534. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | M. albicaulis var. veatchiana | Bartonia albicaulis, M. mojavensis |
Name authority | Kellogg: Proc. Calif. Acad. Sci. 2: 99, fig. 28. (1863) | (Douglas) Douglas ex Torrey & A. Gray: Fl. N. Amer. 1: 534. (1840) |
Web links |