Mentzelia humilis |
Mentzelia memorabilis |
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gypsum blazingstar |
nine-eleven blazingstar, september 11 stickleaf |
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Habit | Plants perennial, bushlike, with ground-level caudices. | Plants perennial, bushlike, with subterranean caudices. | ||||
Stems | solitary or multiple, erect, straight; branches distal or along entire stem, distal longest or all ± equal, antrorse; straight to upcurved; hairy. |
multiple, erect, straight; branches distal, distal longest, antrorse, straight; hairy. |
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Leaves | blade 25–95 × 5.5–28(–36.2) mm, widest intersinus distance 0.8–9.1 mm; proximal spatulate to oblanceolate or elliptic, margins pinnate to pinnatisect, lobes 4–16(–20), slightly antrorse or perpendicular to leaf axis, 2.3–11.8(–16.4) mm; distal elliptic, lanceolate, spatulate, or linear, base not clasping, margins entire or dentate to pinnatisect, teeth or lobes (0–)4–16, slightly antrorse or perpendicular to leaf axis, 2.3–13.8(–16.9) mm; abaxial surface with simple grappling-hook, needlelike, and sometimes complex grappling-hook trichomes, adaxial surface with simple grappling-hook and needlelike trichomes. |
blade 17–36.6 × 1.1–4.8 mm, widest intersinus distance 1.1–4.8 mm; proximal linear to oblanceolate, margins entire; distal linear, base not clasping, margins entire; abaxial surface with simple grappling-hook, complex grappling-hook, and needlelike trichomes, adaxial surface with simple grappling-hook and needlelike trichomes. |
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Bracts | margins usually entire, rarely pinnate. |
margins entire. |
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Flowers | petals white, 10.3–13(–28.6) × 1.4–4 mm, apex acute, glabrous abaxially; stamens white, 5 outermost petaloid, filaments linear to narrowly spatulate, slightly clawed, 8.8–19(–22.3) × 0.7–3.3 mm, without anthers, second whorl without anthers; anthers straight after dehiscence, epidermis papillate; styles 6.5–11.3 mm. |
petals golden yellow, 7.4–11 × 2.6–3.4 mm, apex rounded, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 5.5–9.1 × 1.4–2.7 mm, with anthers, second whorl with anthers; anthers twisted or straight after dehiscence, epidermis smooth; styles 4.8–8 mm. |
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Capsules | cup-shaped, 5.3–10.2 × (4.2–)5.2–8.6 mm, base rounded, not longitudinally ridged. |
cup-shaped, 3.6–5.3 × 3.1–4.2 mm, base rounded, not longitudinally ridged. |
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Seeds | coat anticlinal cell walls wavy, papillae 6–12 per cell. |
coat anticlinal cell walls straight, papillae 6–10 per cell. |
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Mentzelia humilis |
Mentzelia memorabilis |
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Phenology | Flowering Jun–Sep. | |||||
Habitat | Barren gypsum-clay outcrops and hilltops. | |||||
Elevation | 1400–1700 m. (4600–5600 ft.) | |||||
Distribution |
NM; TX
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AZ |
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Discussion | Varieties 2 (2 in the flora). The basionym of Mentzelia humilis is often cited as M. multiflora var. humilis A. Gray (1852). However, in that publication Gray indicated accepted names in Roman capitals (see ipni.org), whereas the varietal name is in lower case, indicating that he was using it as a descriptive term rather than a scientific name. Valid publication of the basionym thus must be attributed to Urban and Gilg. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Mentzelia memorabilis occurs on the Uinkaret Plateau in Mohave County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 12, p. 503. | FNA vol. 12, p. 512. | ||||
Parent taxa | Loasaceae > Mentzelia > sect. Bartonia | Loasaceae > Mentzelia > sect. Bartonia | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | M. pumila var. humilis, Nuttallia humilis, Touterea humilis | |||||
Name authority | (Urban & Gilg) J. Darlington: Ann. Missouri Bot. Gard. 21: 155. (1934) | N. H. Holmgren & P. K. Holmgren: Syst. Bot. 27: 753, fig. 4. (2002) — (as memorabalis) | ||||
Web links |