Mentzelia pectinata |
Mentzelia flumensevera |
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San Joaquin blazing star |
Sevier Canyon stickleaf |
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Habit | Plants candelabra-form, (8–)20–50(–60) cm. | Plants perennial, bushlike, with subterranean caudices or rhizomes. |
Stems | multiple, erect or decumbent, zigzag; branches along entire stem, all ± equal, antrorse, upcurved; hairy. |
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Leaves | blade 11.2–22 × 5.2–10.2 mm, widest intersinus distance 1.2–2.4 mm; proximal oblanceolate to elliptic, margins pinnate, lobes 4–6, perpendicular to leaf axis, 2.3–4.1 mm; distal elliptic, base not clasping, margins pinnate, lobes 2–4, perpendicular to leaf axis, 1.4–3 mm; abaxial surface with complex grappling-hook and needlelike trichomes, adaxial surface with complex 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. |
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, 10–11.2 × 2.9–3.8 mm, apex rounded, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 7.3–8.4 × 1.3–1.9 mm, with anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 5.8–8.7 mm. |
Capsules | clavate, 12–35 × 2–4 mm, axillary curved to 90° at maturity, usually inconspicuously longitudinally ribbed. |
cup-shaped, 5.6–7.1 × 4–6 mm, base rounded, 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 3–7 per cell. |
2n | = 18. |
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Mentzelia pectinata |
Mentzelia flumensevera |
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Phenology | Flowering Mar–May. | Flowering Jul–Aug(–Oct). |
Habitat | Slopes of sandy or gray-white silty soils, grasslands, oak savannas, uncommonly juniper woodlands. | Sparsely vegetated, steep talus slopes composed of gravel and clay, white soils. |
Elevation | 200–1400 m. (700–4600 ft.) | 1700–1900 m. (5600–6200 ft.) |
Distribution |
CA
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UT |
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.) |
Mentzelia flumensevera is narrowly distributed across the Piute and Sevier county line. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 541. | FNA vol. 12, p. 511. |
Parent taxa | Loasaceae > Mentzelia > sect. Trachyphytum | Loasaceae > Mentzelia > sect. Bartonia |
Sibling taxa | ||
Synonyms | M. multicaulis var. flumensevera | |
Name authority | Kellogg: Proc. Calif. Acad. Sci. 3: 40, fig. 9. (1863) | (N. H. Holmgren & P. K. Holmgren) J. J. Schenk & L. Hufford: Novon 19: 118. (2009) |
Web links |