Mentzelia albescens |
Mentzelia rhizomata |
|
---|---|---|
wavy-leaf blazingstar |
Roan Cliffs blazingstar |
|
Habit | Plants biennial, candelabra-form. | Plants perennial, bushlike, with rhizomes. |
Stems | solitary, erect, straight; branches distal, distal longest, antrorse, straight; hairy. |
multiple, erect or decumbent, zigzag; branches along entire stem, distal longest, 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 8.1–29 × 4.1–12.7 mm, widest intersinus distance 4.1–7.4 mm; proximal oblanceolate, margins entire; distal elliptic, base not clasping, margins entire or dentate, teeth 0–8, perpendicular to leaf axis, 0.6–2.7 mm; abaxial surface 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 golden yellow, 12.5–17.2 × 6.1–11.2 mm, apex rounded to obtuse, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, strongly clawed, 7–9.5 × 2.7–6 mm, with anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 7–10 mm. |
Capsules | cylindric, 13.6–23.5 × 5.1–7.8 mm, base tapering, not or slightly longitudinally ridged. |
cup-shaped, 7–10 × 6.5–8 mm, base rounded, not longitudinally ridged. |
Seeds | coat anticlinal cell walls straight, papillae 4–17 per cell. |
coat anticlinal cell walls straight, papillae 9–13 per cell. |
2n | = 22. |
|
Mentzelia albescens |
Mentzelia rhizomata |
|
Phenology | Flowering May–Nov. | Flowering Jul–Aug. |
Habitat | Dry grasslands, xeric habitats of arroyos, roadsides, roadcuts, washes, chat piles, slopes. | Sparsely vegetated, steep talus slopes with loose gravelly soils. |
Elevation | 200–1600 m. (700–5200 ft.) | 1700–2100 m. (5600–6900 ft.) |
Distribution |
KS; MO; OK; TX; South America (Argentina, Chile) |
CO |
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 rhizomata is known only from Garfield County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 518. | FNA vol. 12, p. 513. |
Parent taxa | Loasaceae > Mentzelia > sect. Bartonia | Loasaceae > Mentzelia > sect. Bartonia |
Sibling taxa | ||
Synonyms | Bartonia albescens, B. wrightii | Nuttallia rhizomata |
Name authority | (Gillies ex Arnott) Bentham & Hooker f. ex Grisebach: Abh. Königl. Ges. Wiss. Göttingen 19: 150. (1874) | Reveal: Syst. Bot. 27: 763, figs. 1, 2. (2002) |
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