Mentzelia decapetala |
Mentzelia laevicaulis |
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10-petal western star, evening starflower, gumbo-lily, tenpetal blazingstar |
blazing-star mentzelia, common blazing-star, giant blazing-star, smooth-stem blazingstar |
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Habit | Plants biennial or perennial, bushlike, perennials with ground-level caudices. | Plants biennial or perennial (in rosette stage), bushlike. | ||||
Stems | solitary, erect, straight; branches distal or along entire stem, proximal or distal longest, antrorse, straight to upcurved; hairy. |
solitary, erect, straight; branches distal or along entire stem, proximal or distal longest, antrorse, upcurved; hairy or glabrescent. |
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Leaves | blade 72–295 × 14–45 mm, widest intersinus distance 10.1–23.3 mm; proximal oblanceolate or elliptic, margins serrate to pinnate, teeth or lobes 16–26, slightly antrorse, 1–16.5 mm; distal elliptic to lanceolate, base clasping or not, margins serrate to pinnate, teeth or lobes 9–20, slightly antrorse, 5.3–13.7 mm; surfaces with needlelike trichomes. |
blade 17.4–196 × 6.7–40.4 mm, widest intersinus distance 2.4–24.6 mm; proximal oblanceolate, lanceolate, or elliptic, margins pinnate, lobes 14–44, slightly antrorse, 2.5–8.9 mm; distal lanceolate, base clasping or not, margins pinnate, lobes 6–42, slightly antrorse, 2.1–13.8 mm; abaxial surface with simple grappling-hook, complex grappling-hook, and needlelike trichomes, adaxial surface with needlelike trichomes. |
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Bracts | margins pinnate. |
margins entire or pinnate. |
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Flowers | petals white, 47–75 × 13–22.7 mm, apex acute to attenuate, glabrous abaxially; stamens white to yellow, 5 outermost petaloid, filaments spatulate, strongly clawed, 48–75 × 12–23 mm, without anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 36–53 mm. |
petals golden yellow, 23.5–70 × 3–17.3 mm, apex acute, glabrous abaxially; stamens golden yellow, 5 outermost not petaloid, filaments linear to narrowly elliptic, not clawed, 17.7–55 × 0.5–2(–2.5) mm, with anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 20.4–57 mm. |
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Capsules | cylindric, 30–43 × 12–17 mm, base tapering, not longitudinally ridged. |
cup-shaped to cylindric, 10.6–43 × 6.3–11.1 mm, base tapering or rounded, not longitudinally ridged. |
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Seeds | 2.3–4 mm; coat anticlinal cell walls straight, papillae 4–10 per cell. |
coat anticlinal cell walls straight, papillae 4–11 per cell. |
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2n | = 22. |
= 22. |
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Mentzelia decapetala |
Mentzelia laevicaulis |
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Phenology | Flowering Jun–Aug(–Oct). | |||||
Habitat | Rock outcrops, slopes, dry short-grass prairies, riverbanks, roadsides, loam, limestone, sandy, silty, clayey, and gravelly soils. | |||||
Elevation | 300–2400 m. (1000–7900 ft.) | |||||
Distribution |
CO; IA; IL; KS; MN; MT; NE; NM; OK; SD; TX; UT; WY; AB; MB; SK
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AZ; CA; ID; MT; NV; OR; UT; WA; WY; BC
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Discussion | Mentzelia decapetala is introduced in Grundy County, Illinois. It appears to be native throughout the rest of its distribution. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 2 (2 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 12, p. 504. | FNA vol. 12, p. 514. | ||||
Parent taxa | Loasaceae > Mentzelia > sect. Bartonia | Loasaceae > Mentzelia > sect. Bartonia | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Bartonia decapetala | Bartonia laevicaulis | ||||
Name authority | (Pursh) Urban: Ber. Deutsch. Bot. Ges. 10: 263. (1892) | (Douglas) Torrey & A. Gray: Fl. N. Amer. 1: 535. (1840) | ||||
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