Mentzelia albescens |
Mentzelia oreophila |
|
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wavy-leaf blazingstar |
Argus blazingstar, mountain loving blazing star |
|
Habit | Plants biennial, candelabra-form. | Plants perennial, bushlike, with subterranean caudices. |
Stems | solitary, erect, straight; branches distal, distal longest, antrorse, straight; hairy. |
multiple, erect, straight; branches distal or along entire stem, distal longest or all ± equal, antrorse, upcurved; hairy. |
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. |
blade 17–103 × 7.6–41.2 mm, widest intersinus distance 5.1–35.3 mm; proximal oblanceolate to elliptic, margins serrate, teeth 6–22, slightly antrorse, 0.4–5.3 mm; distal elliptic, lanceolate, or deltate, base clasping, margins serrate, teeth 6–16, slightly antrorse, 0.5–4.2 mm; abaxial surface with complex grappling-hook trichomes, adaxial surface with complex grappling-hook and needlelike trichomes, both surfaces green, moderately hairy. |
Bracts | margins entire. |
margins entire. |
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 golden yellow, 7–14.5(–16.2) × 1.7–5.2 mm, apex rounded, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 5.3–11.1(–15.4) × 0.6–4.4 mm, with anthers, second whorl with anthers; anthers twisted after dehiscence, epidermis smooth; styles 3.8–8.1 mm. |
Capsules | cylindric, 13.6–23.5 × 5.1–7.8 mm, base tapering, not or slightly longitudinally ridged. |
cup-shaped, 5.8–9 × 5.2–8.8 mm, base rounded, not longitudinally ridged. |
Seeds | coat anticlinal cell walls straight, papillae 4–17 per cell. |
coat anticlinal cell walls straight, papillae 6–17 per cell. |
2n | = 22. |
= 22. |
Mentzelia albescens |
Mentzelia oreophila |
|
Phenology | Flowering May–Nov. | Flowering Feb–Oct. |
Habitat | Dry grasslands, xeric habitats of arroyos, roadsides, roadcuts, washes, chat piles, slopes. | Sparsely vegetated slopes, roadcuts, loose, rocky and sandy limestone soils. |
Elevation | 200–1600 m. (700–5200 ft.) | 400–1600 m. (1300–5200 ft.) |
Distribution |
KS; MO; OK; TX; South America (Argentina, Chile) |
CA; NV
|
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 oreophila is found in Inyo, Riverside, and San Bernardino counties, California, and Clark, Esmeralda, Lincoln, and Nye counties, Nevada. The California populations have a smaller stature than those in Nevada, and phylogenetic analysis indicated that the species is potentially polyphyletic. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 518. | FNA vol. 12, p. 510. |
Parent taxa | Loasaceae > Mentzelia > sect. Bartonia | Loasaceae > Mentzelia > sect. Bartonia |
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) | J. Darlington: Ann. Missouri Bot. Gard. 21: 175. (1934) |
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