Mentzelia albescens |
Mentzelia pumila |
|
---|---|---|
wavy-leaf blazingstar |
dwarf blazingstar, dwarf mentzelia, golden blazingstar |
|
Habit | Plants biennial, candelabra-form. | Plants biennial, candelabra-form. |
Stems | solitary, erect, straight; branches distal, distal longest, antrorse, straight; hairy. |
solitary, erect, straight; branches distal, distal 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 19–82 × 4.8–22.1 mm, widest intersinus distance 2.7–6.7 mm; proximal oblanceolate to elliptic, margins serrate to pinnate, teeth or lobes 10–22, slightly antrorse or perpendicular to leaf axis, 1–5.5 mm; distal elliptic to lanceolate, base not clasping, margins pinnate, lobes 8–14, usually perpendicular to leaf axis, 0.8–7 mm; abaxial surface with simple grappling-hook and complex grappling-hook trichomes, adaxial surface with simple grappling-hook and needlelike trichomes. |
Bracts | margins entire. |
margins entire or 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 golden yellow, 7.6–12.3 × 2–3.8 mm, apex usually acute, occasionally rounded, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 6.4–11.8 × 1.1–2.7 mm, without anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 5.6–7.8 mm. |
Capsules | cylindric, 13.6–23.5 × 5.1–7.8 mm, base tapering, not or slightly longitudinally ridged. |
cylindric, 10.8–20 × 5.3–7.6 mm, length more than 2 times diam., base tapering, not longitudinally ridged. |
Seeds | coat anticlinal cell walls straight, papillae 4–17 per cell. |
coat anticlinal cell walls straight, papillae 4–5 per cell. |
2n | = 22. |
= 22. |
Mentzelia albescens |
Mentzelia pumila |
|
Phenology | Flowering May–Nov. | Flowering May–Aug. |
Habitat | Dry grasslands, xeric habitats of arroyos, roadsides, roadcuts, washes, chat piles, slopes. | Hillside slopes, sandy and clayey soils. |
Elevation | 200–1600 m. (700–5200 ft.) | 1100–2500 m. (3600–8200 ft.) |
Distribution |
KS; MO; OK; TX; South America (Argentina, Chile) |
CO; MT; WY
|
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.) |
The name Mentzelia pumila has been applied variously in regional floras and in other taxonomic treatments of Mentzelia; however, we follow R. J. Hill (1975) and N. H. Holmgren et al. (2005), which are consistent with our phylogenetic results (J. J. Schenk and L. Hufford 2011), in treating M. pumila as a species found only in Wyoming and adjacent areas of Colorado and Montana. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 518. | FNA vol. 12, p. 519. |
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) | Torrey & A. Gray: Fl. N. Amer. 1: 535. (1840) |
Web links |