Mentzelia albescens |
Mentzelia chrysantha |
|
---|---|---|
wavy-leaf blazingstar |
gold blazingstar, golden blazingstar |
|
Habit | Plants biennial, candelabra-form. | Plants biennial, bushlike or candelabra-form. |
Stems | solitary, erect, straight; branches distal, distal longest, antrorse, straight; hairy. |
solitary, erect, straight; branches distal or along entire stem, distal or proximal longest, antrorse, straight; 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 38–113 × 8–20.5(–25.2) mm, widest intersinus distance 5.4–12.8 mm; proximal oblanceolate, lanceolate, or elliptic, margins serrate to pinnate, teeth or lobes 14–22, slightly antrorse, 0.6–4.6 mm; distal elliptic or lanceolate, base not clasping, margins serrate to pinnate, teeth or lobes 6–22, slightly antrorse, 0.6–4 mm; abaxial surface with simple grappling-hook, complex grappling-hook, and needlelike trichomes, adaxial surface with simple grappling-hook and needlelike trichomes. |
Bracts | margins entire. |
margins toothed. |
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 light to golden yellow, 12.5–21.4 × 3.8–6.7 mm, apex acute to rounded, glabrous abaxially; stamens light to golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 11.5–18.6 × 2–5.8 mm, without anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 8.1–13.1 mm. |
Capsules | cylindric, 13.6–23.5 × 5.1–7.8 mm, base tapering, not or slightly longitudinally ridged. |
cup-shaped to cylindric, 9.4–16 × 5.1–7.7 mm, base tapering, not longitudinally ridged. |
Seeds | coat anticlinal cell walls straight, papillae 4–17 per cell. |
coat anticlinal cell walls sinuous, papillae 29–35 per cell. |
2n | = 22. |
= 20. |
Mentzelia albescens |
Mentzelia chrysantha |
|
Phenology | Flowering May–Nov. | Flowering Jul–Sep. |
Habitat | Dry grasslands, xeric habitats of arroyos, roadsides, roadcuts, washes, chat piles, slopes. | Steep hillsides, washes, clayey soils, sometimes rich in gypsum. |
Elevation | 200–1600 m. (700–5200 ft.) | 1600–1900 m. (5200–6200 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 chrysantha occurs in Custer and Fremont counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 518. | FNA vol. 12, p. 523. |
Parent taxa | Loasaceae > Mentzelia > sect. Bartonia | Loasaceae > Mentzelia > sect. Bartonia |
Sibling taxa | ||
Synonyms | Bartonia albescens, B. wrightii | Nuttallia chrysantha |
Name authority | (Gillies ex Arnott) Bentham & Hooker f. ex Grisebach: Abh. Königl. Ges. Wiss. Göttingen 19: 150. (1874) | Engelmann: Bull. U.S. Geol. Geogr. Surv. Territ. 2: 237. (1876) |
Web links |