Mentzelia decapetala |
Mentzelia pterosperma |
|
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10-petal western star, evening starflower, gumbo-lily, tenpetal blazingstar |
wing-seed blazing star, wingseed stickleaf |
|
Habit | Plants biennial or perennial, bushlike, perennials with ground-level caudices. | Plants winter annual or biennial, candelabra-form. |
Stems | solitary, erect, straight; branches distal or along entire stem, proximal or distal longest, antrorse, straight to upcurved; hairy. |
solitary, erect, straight; branches distal, distal longest, antrorse, straight, hairy. |
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 13.8–78 × 3.8–20 mm, widest intersinus distance 2.5–15.8 mm; proximal oblanceolate to elliptic, margins entire or serrate to pinnate, teeth or lobes (0–)8–14(–22), slightly antrorse, 0.3–5.3 mm; distal elliptic to lanceolate, base usually clasping, rarely a few not clasping, margins usually serrate to pinnate, occasionally entire, teeth or lobes (0–)6–18, slightly antrorse, 2.8–4.3(–6.1) mm; abaxial surface with simple grappling-hook, occasionally complex grappling-hook, and rarely needlelike trichomes, adaxial surface occasionally with simple grappling-hook and needlelike trichomes. |
Bracts | margins pinnate. |
margins usually entire, rarely pinnate. |
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, 6.4–17(–20) × 2–5.3 mm, apex usually acute, occasionally rounded, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments linear to oblanceolate, slightly clawed, 6.2–14.2(–17.5) × 1–3.9 mm, usually without, rarely with, anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 6–11 mm. |
Capsules | cylindric, 30–43 × 12–17 mm, base tapering, not longitudinally ridged. |
cup-shaped, 7.3–13.7 × 5.5–9.8 mm, base rounded, not longitudinally ridged. |
Seeds | 2.3–4 mm; coat anticlinal cell walls straight, papillae 4–10 per cell. |
coat anticlinal cell walls straight, papillae 5–18 per cell. |
2n | = 22. |
= 22. |
Mentzelia decapetala |
Mentzelia pterosperma |
|
Phenology | Flowering Jun–Aug(–Oct). | Flowering Apr–Jun(–Jul). |
Habitat | Rock outcrops, slopes, dry short-grass prairies, riverbanks, roadsides, loam, limestone, sandy, silty, clayey, and gravelly soils. | Disturbed soils, washes, sand dunes, roadcuts, badland knolls, clayey soils, gravelly soils with sandy or gypsum-rich clay. |
Elevation | 300–2400 m. (1000–7900 ft.) | 300–1900 m. (1000–6200 ft.) |
Distribution |
CO; IA; IL; KS; MN; MT; NE; NM; OK; SD; TX; UT; WY; AB; MB; SK
|
AZ; CA; CO; NV; UT
|
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.) |
Mentzelia pterosperma occurs in the Colorado Plateau and Mojave Desert. Mojave Desert populations occur from eastern San Bernardino and southeastern Inyo counties, California, through Clark County, Nevada. Colorado Plateau populations are common in northern Arizona and extend northward to Utah and western Colorado. Populations in Utah occur in habitats composed of gravelly soils that are sandy or gypsum-rich clay, whereas Arizona and Nevada populations occur primarily on clayey soils, which sometimes contain gypsum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 504. | FNA vol. 12, p. 517. |
Parent taxa | Loasaceae > Mentzelia > sect. Bartonia | Loasaceae > Mentzelia > sect. Bartonia |
Sibling taxa | ||
Synonyms | Bartonia decapetala | |
Name authority | (Pursh) Urban: Ber. Deutsch. Bot. Ges. 10: 263. (1892) | Eastwood: Proc. Calif. Acad. Sci., ser. 2, 6: 290. (1896) |
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