Mentzelia albescens |
Mentzelia hualapaiensis |
|
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wavy-leaf blazingstar |
Hualapai blazingstar |
|
Habit | Plants biennial, candelabra-form. | Plants perennial, bushlike, with subterranean caudices. |
Stems | solitary, erect, straight; branches distal, distal longest, antrorse, straight; hairy. |
multiple, erect, zigzag or 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 17–94 × 12–32 mm, widest intersinus distance 9.5–29 mm; proximal broadly spatulate to elliptic, margins serrate, teeth 6–12, slightly antrorse or perpendicular to leaf axis, 0.4–1.5 mm; distal broadly spatulate, elliptic, or obovate, base not clasping, margins serrate, teeth 8–10, slightly antrorse or perpendicular to leaf axis, 1–3.6 mm; abaxial surface with complex grappling-hook and occasionally with simple grappling-hook and needlelike trichomes, adaxial surface with needlelike trichomes. |
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 white to light yellow, 9.4–17.4(–20) × 1.7–4.3 mm, apex acute to rounded, glabrous abaxially; stamens white to light yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 8.5–18 × 1–1.3(–2.9) mm, without anthers, second whorl with anthers; anthers straight after dehiscence, epidermis papillate; styles 5.8–9 mm. |
Capsules | cylindric, 13.6–23.5 × 5.1–7.8 mm, base tapering, not or slightly longitudinally ridged. |
cup-shaped, 4.9–10.3 × 4.6–8.6 mm, base rounded, not longitudinally ridged. |
Seeds | coat anticlinal cell walls straight, papillae 4–17 per cell. |
coat anticlinal cell walls straight to slightly wavy, papillae 8–14 per cell. |
2n | = 22. |
|
Mentzelia albescens |
Mentzelia hualapaiensis |
|
Phenology | Flowering May–Nov. | Flowering Mar–Jun(–Sep). |
Habitat | Dry grasslands, xeric habitats of arroyos, roadsides, roadcuts, washes, chat piles, slopes. | Rocky desert scrub, gravelly canyon bottoms, steep travertine, shaley slopes associated with Muav limestone formations. |
Elevation | 200–1600 m. (700–5200 ft.) | 400–1400 m. (1300–4600 ft.) |
Distribution |
KS; MO; OK; TX; South America (Argentina, Chile) |
AZ |
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 hualapaiensis is distributed in Coconino and Mohave counties along the Grand Canyon and its side canyons between the Upper and Lower Granite Gorge. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 518. | FNA vol. 12, p. 502. |
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. J. Schenk: W. C. Hodgson & L. Hufford, Brittonia 62: 1, figs. 1, 2A,C–E. (2010) |
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