Mentzelia decapetala |
Mentzelia cronquistii |
|
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10-petal western star, evening starflower, gumbo-lily, tenpetal blazingstar |
Cronquist's blazingstar |
|
Habit | Plants biennial or perennial, bushlike, perennials with ground-level caudices. | Plants 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 or along entire stem, proximal longer than distal, all usually extending to near the distal end of plant, 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 21–101 × 4–10.7(–19.3) mm, widest intersinus distance 1.8–7.3(–12.6) mm; proximal oblanceolate, lanceolate, or elliptic, margins dentate to pinnate, teeth or lobes 8–28, perpendicular to leaf axis, 1.2–6(–9) mm, always some more than 4 mm; distal oblanceolate, elliptic, or lanceolate, base not clasping, margins dentate to pinnate, teeth or lobes 6–18, perpendicular to leaf axis, 1.1–5(–6.9) mm; abaxial surface with simple grappling-hook, complex grappling-hook, and needlelike trichomes, adaxial surface with simple grappling-hook, needlelike, and occasionally complex grappling-hook trichomes. |
Bracts | margins pinnate. |
margins entire or toothed to 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, 9–16.6 × 2.5–5.1 mm, apex usually rounded, rarely acute, hairy abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 7.3–13.2 × 1.8–4.3 mm, usually without, rarely with anthers, second whorl with anthers; anthers straight after dehiscence, epidermis papillate or not; styles 6.5–10 mm. |
Capsules | cylindric, 30–43 × 12–17 mm, base tapering, not longitudinally ridged. |
cup-shaped, 5.9–10.6(–11.4) × 5–7.6 mm, base tapering to rounded, not longitudinally ridged. |
Seeds | 2.3–4 mm; coat anticlinal cell walls straight, papillae 4–10 per cell. |
coat anticlinal cell walls wavy, papillae 8–13 per cell. |
2n | = 22. |
= 20. |
Mentzelia decapetala |
Mentzelia cronquistii |
|
Phenology | Flowering Jun–Aug(–Oct). | Flowering May–Nov. |
Habitat | Rock outcrops, slopes, dry short-grass prairies, riverbanks, roadsides, loam, limestone, sandy, silty, clayey, and gravelly soils. | Sandy and rocky soils, washes, roadside banks, steep slopes. |
Elevation | 300–2400 m. (1000–7900 ft.) | 800–2300 m. (2600–7500 ft.) |
Distribution |
CO; IA; IL; KS; MN; MT; NE; NM; OK; SD; TX; UT; WY; AB; MB; SK
|
AZ; CO; NM; 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.) |
|
Source | FNA vol. 12, p. 504. | FNA vol. 12, p. 506. |
Parent taxa | Loasaceae > Mentzelia > sect. Bartonia | Loasaceae > Mentzelia > sect. Bartonia |
Sibling taxa | ||
Synonyms | Bartonia decapetala | M. marginata var. cronquistii, Nuttallia cronquistii |
Name authority | (Pursh) Urban: Ber. Deutsch. Bot. Ges. 10: 263. (1892) | H. J. Thompson & Prigge: Great Basin Naturalist 46: 550, figs. 2, 3A,B, 4A. (1986) |
Web links |