Mentzelia albescens |
Mentzelia torreyi |
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wavy-leaf blazingstar |
Torrey's blazing star |
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Habit | Plants biennial, candelabra-form. | Plants with ground-level or subterranean caudices. | ||||
Stems | solitary, erect, straight; branches distal, distal longest, antrorse, straight; hairy. |
5–25 cm. |
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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. |
petiole absent; blade ovate or obovate, to 45 × 35 mm, intersinus distance 2–4 mm. |
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Bracts | margins entire. |
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Pedicels | 0(–1.5) mm. |
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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 yellow to orange, narrowly spatulate to obovate, 4.5–17 × 1.2–5 mm, apex rounded; stamens 25–45, 7–21 mm; styles 7–18 mm. |
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Capsules | cylindric, 13.6–23.5 × 5.1–7.8 mm, base tapering, not or slightly longitudinally ridged. |
3–7 × 3–4.5 mm. |
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Seeds | coat anticlinal cell walls straight, papillae 4–17 per cell. |
3–9 per capsule, edges prominently to inconspicuously ridged. |
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2n | = 22. |
= 28. |
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Mentzelia albescens |
Mentzelia torreyi |
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Phenology | Flowering May–Nov. | |||||
Habitat | Dry grasslands, xeric habitats of arroyos, roadsides, roadcuts, washes, chat piles, slopes. | |||||
Elevation | 200–1600 m. (700–5200 ft.) | |||||
Distribution |
KS; MO; OK; TX; South America (Argentina, Chile) |
CA; ID; 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.) |
Varieties 2 (2 in flora). In the phylogenetic study by L. Hufford et al. (2003), Mentzelia torreyi was recovered as the sister to the rest of the genus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 12, p. 518. | FNA vol. 12, p. 530. | ||||
Parent taxa | Loasaceae > Mentzelia > sect. Bartonia | Loasaceae > Mentzelia > sect. Micromentzelia | ||||
Sibling taxa | ||||||
Subordinate 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: Proc. Amer. Acad. Arts 10: 72. (1874) | ||||
Web links |