Mentzelia nitens |
Mentzelia mexicana |
|
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shining blazing star, Venus blazingstar |
Mexican blazingstar, Mexico blazingstar |
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Habit | Plants candelabra-form, 5–20(–35) cm. | Plants biennial, bushlike or candelabra-form. |
Stems | solitary, erect, straight; branches distal or along entire stem, distal or proximal longest, antrorse, upcurved; hairy. |
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Leaves | blade 24–82 × 11.7–29.1 mm, widest intersinus distance 3.4–19 mm; proximal oblanceolate or elliptic, margins dentate, serrate, or pinnate, teeth or lobes 6–16, slightly antrorse or perpendicular to leaf axis, 1.4–5.1 mm; distal elliptic to lanceolate, base usually not clasping, sometimes a few clasping, margins dentate, serrate, or pinnate, teeth or lobes 6–12, slightly antrorse or perpendicular to leaf axis, 2.5–6.7 mm; abaxial surface with simple grappling-hook, complex grappling-hook, and usually needlelike trichomes, adaxial surface with simple grappling-hook and needlelike trichomes. |
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Basal leaves | persisting; petiole present or absent; blade lanceolate to linear, margins usually deeply to shallowly lobed, rarely entire. |
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Cauline leaves | petiole absent; blade ovate-lanceolate to linear, to 15 cm, margins deeply to shallowly lobed or entire. |
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Bracts | green, lanceolate, 4.5–8.3 × 1.2–3.6 mm, width 1/5–1/2 length, not concealing capsule, margins entire. |
margins entire. |
Flowers | sepals 3–8 mm; petals yellow to orange proximally, yellow distally, (7–)8–18 mm, apex rounded or acute apex; stamens 20+, 3–8 mm, filaments monomorphic, filiform, unlobed; styles 4–8 mm. |
petals golden yellow, 10.2–15.3(–17) × 2.5–6.2 mm, apex rounded, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 9.9–14.4(–16.7) × 2–4.8 mm, without anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 4.5–10.9 mm. |
Capsules | clavate, 13–26 × 2–3.5 mm, axillary curved to 180° at maturity, usually inconspicuously longitudinally ribbed. |
cup-shaped, 7.1–12.8 × 5.6–8.4 mm, length to 2 times diam., base rounded, not longitudinally ridged. |
Seeds | 15–40, in 2+ rows distal to mid fruit, tan, usually dark-mottled, usually irregularly polygonal, occasionally triangular prisms proximal to mid fruit, surface colliculate under 10x magnification; recurved flap over hilum usually present; seed coat cell outer periclinal wall domed, domes on seed edges less than 1/2 as tall as wide at maturity. |
coat anticlinal cell walls straight, papillae 8–12 per cell. |
2n | = 18. |
= 18. |
Mentzelia nitens |
Mentzelia mexicana |
|
Phenology | Flowering Apr–Jun. | Flowering Mar–Oct. |
Habitat | Sandy washes, rocky slopes, desert scrub. | Arroyos, knolls, steep slopes, gypsum and limestone clay and shale. |
Elevation | 400–2000 m. (1300–6600 ft.) | 700–1500 m. (2300–4900 ft.) |
Distribution |
CA; NV
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TX; Mexico (Chihuahua, Coahuila, Nuevo León, Zacatecas) |
Discussion | Mentzelia nitens is similar to both M. eremophila and M. jonesii but exhibits little distributional overlap with either species. See 71. M. eremophila and 73. M. jonesii for discussion of similarities. Reports of M. nitens from Arizona are based on specimens treated here as M. jonesii. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
In the flora area, Mentzelia mexicana occurs in Brewster, Hudspeth, and Presidio counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 540. | FNA vol. 12, p. 521. |
Parent taxa | Loasaceae > Mentzelia > sect. Trachyphytum | Loasaceae > Mentzelia > sect. Bartonia |
Sibling taxa | ||
Name authority | Greene: Fl. Francisc., 234. (1891) | H. J. Thompson & Zavortink: Wrightia 4: 21. (1968) |
Web links |