Mentzelia albescens |
Mentzelia tricuspis |
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wavy-leaf blazingstar |
desert blazingstar, spiny-hair blazing star, spinyhair stickleaf, three point blazing star |
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Habit | Plants biennial, candelabra-form. | Plants 5–30 cm. |
Stems | solitary, erect, straight; branches distal, distal longest, antrorse, straight; hairy. |
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Leaves | blade 31–92(–157) × 10.5–27.6(–41) mm, widest intersinus distance 5.2–23.3(–29) mm; proximal lanceolate or elliptic, margins serrate to pinnate, teeth or lobes 8–22, slightly antrorse, 1.8–6 mm; distal lanceolate, base clasping, margins usually serrate to pinnate, occasionally entire, teeth or lobes (0–)10–20, slightly antrorse, 1.4–7.6 mm; abaxial surface with simple grappling-hook, complex grappling-hook, and needlelike trichomes, adaxial surface with simple grappling-hook and needlelike trichomes. |
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Basal leaves | petioles present; blade lanceolate, to 12 cm; margins shallowly lobed, lobes rounded. |
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Cauline leaves | petioles usually present, rarely absent; blade broadly ovate to lanceolate, to 12 cm, base not cordate-clasping, margins dentate to serrate. |
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Bracts | margins entire. |
green, inconspicuous, not concealing pedicel, ovary, or capsule. |
Flowers | petals golden yellow, 5.7–9.2 × 1.3–3 mm, apex usually acute, occasionally rounded, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 4.7–8.4 × 1–2.4 mm, without anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 3.5–5.4 mm. |
petals white to pale yellow, obovate, 10–30(–50) mm, apex mucronate; stamens 7–17 mm, less than 1/2 petal length, all fertile, none petaloid (flowers appearing to have 5 petals); filaments ± monomorphic, linear, distally 2-lobed, lobes 0.6–2.5 mm; anther stalk usually shorter than filament lobes; style 10–15 mm. |
Capsules | cylindric, 13.6–23.5 × 5.1–7.8 mm, base tapering, not or slightly longitudinally ridged. |
cylindric to ovoid, 9–18(–23) × 5–8 mm, proximal nodding, distal erect. |
Seeds | coat anticlinal cell walls straight, papillae 4–17 per cell. |
constricted and grooved at middle; seed coat anticlinal cell walls straight to slightly wavy, conspicuous. |
2n | = 22. |
= 20. |
Mentzelia albescens |
Mentzelia tricuspis |
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Phenology | Flowering May–Nov. | Flowering Mar–May. |
Habitat | Dry grasslands, xeric habitats of arroyos, roadsides, roadcuts, washes, chat piles, slopes. | Sandy or gravelly slopes, washes, desert scrub. |
Elevation | 200–1600 m. (700–5200 ft.) | 150–1300 m. (500–4300 ft.) |
Distribution |
KS; MO; OK; TX; South America (Argentina, Chile) |
AZ; CA; NV
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Discussion | Phylogenetic analyses (J. J. Schenk and L. Hufford 2011) recovered representative populations of Mentzelia albescens from Texas and South America in a monophyletic group. Phylogenetic placement of these populations among lineages in sect. Bartonia, as well as a lack of morphological differentiation among North American and South American populations, suggests a recent dispersal to South America. In the flora area, this species is native to central and western Texas, and introduced in Kansas, Missouri, and Oklahoma. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Mentzelia tricuspis is morphologically most similar to M. tridentata with differences largely limited to the lengths of the stamen filament lobes (and thus relative lengths of the anther stalks) and shapes of the seeds. However, the species are also distinct geographically, with M. tricuspis found in the southeastern Mojave Desert and northwestern Sonoran Desert and M. tridentata in the central to western Mojave Desert. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 518. | FNA vol. 12, p. 526. |
Parent taxa | Loasaceae > Mentzelia > sect. Bartonia | Loasaceae > Mentzelia > sect. Bicuspidaria |
Sibling taxa | ||
Synonyms | Bartonia albescens, B. wrightii | |
Name authority | (Gillies ex Arnott) Bentham & Hooker f. ex Grisebach: Abh. Königl. Ges. Wiss. Göttingen 19: 150. (1874) | A. Gray: Amer. Naturalist 9: 271. (1875) |
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