Mentzelia pectinata |
Mentzelia pumila |
|
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San Joaquin blazing star |
dwarf blazingstar, dwarf mentzelia, golden blazingstar |
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Habit | Plants candelabra-form, (8–)20–50(–60) cm. | Plants biennial, candelabra-form. |
Stems | solitary, erect, straight; branches distal, distal longest, antrorse, straight; hairy. |
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Leaves | 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. |
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Basal leaves | persisting; petiole present or absent; blade lanceolate to linear, margins deeply to shallowly lobed. |
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Cauline leaves | petiole absent; blade ovate to linear, to 12 cm, margins deeply lobed to dentate. |
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Bracts | green, ovate to lanceolate, 6.6–12.8 × 1.9–6.8 mm, width 1/5–2/3 length, not concealing capsule, margins 3–7-lobed. |
margins entire or toothed. |
Flowers | sepals 3–13 mm; petals red to orange proximally, orange to yellow distally, 8–22 mm, apex mucronate, rounded, or retuse; stamens 20+, 4–11 mm, filaments monomorphic, filiform, unlobed; styles 5–13 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 | clavate, 12–35 × 2–4 mm, axillary curved to 90° at maturity, usually inconspicuously longitudinally ribbed. |
cylindric, 10.8–20 × 5.3–7.6 mm, length more than 2 times diam., base tapering, not longitudinally ridged. |
Seeds | 20–40, in 2+ rows distal to mid fruit, tan, dark-mottled or not, usually irregularly polygonal, occasionally triangular prisms proximal to mid fruit, surface tuberculate under 10x magnification; recurved flap over hilum absent; seed coat cell outer periclinal wall domed, domes on seed edges more than 1/2 as tall as wide at maturity. |
coat anticlinal cell walls straight, papillae 4–5 per cell. |
2n | = 18. |
= 22. |
Mentzelia pectinata |
Mentzelia pumila |
|
Phenology | Flowering Mar–May. | Flowering May–Aug. |
Habitat | Slopes of sandy or gray-white silty soils, grasslands, oak savannas, uncommonly juniper woodlands. | Hillside slopes, sandy and clayey soils. |
Elevation | 200–1400 m. (700–4600 ft.) | 1100–2500 m. (3600–8200 ft.) |
Distribution |
CA
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CO; MT; WY
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Discussion | Mentzelia pectinata occurs in Kern, San Luis Obispo, Santa Barbara, and Tulare counties, around the southern rim of the San Joaquin Valley, extending into the Inner Coast Ranges and the southern foothills of the Sierra Nevada. Petal color varies from orange to yellow, and fully fertile artificial hybrids have been obtained between populations representing the extreme phenotypes (J. E. Zavortink 1966). Phylogenetic studies suggest that M. pectinata and M. congesta have hybridized to form several allopolyploid species (J. M. Brokaw and L. Hufford 2010b) despite their current allopatric distributions. (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. 541. | FNA vol. 12, p. 519. |
Parent taxa | Loasaceae > Mentzelia > sect. Trachyphytum | Loasaceae > Mentzelia > sect. Bartonia |
Sibling taxa | ||
Name authority | Kellogg: Proc. Calif. Acad. Sci. 3: 40, fig. 9. (1863) | Torrey & A. Gray: Fl. N. Amer. 1: 535. (1840) |
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