Mentzelia pectinata |
Mentzelia multicaulis |
|
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San Joaquin blazing star |
manystem blazingstar, multiple-branch blazingstar |
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Habit | Plants candelabra-form, (8–)20–50(–60) cm. | Plants perennial, bushlike, with subterranean caudices or sometimes rhizomes. |
Stems | multiple, erect or decumbent, zigzag or straight; branches distal or along entire stem, distal longest or all ± equal, antrorse, straight to upcurved; hairy. |
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Leaves | blade 20–49(–57) × 4.2–19 mm, widest intersinus distance 1.1–5.3 mm; proximal oblanceolate to elliptic, margins pinnate to pinnatisect, lobes 4–10, slightly antrorse, 0.7–7.6 mm; distal linear to lanceolate, base not clasping, margins entire or pinnate, lobes 0–10, slightly antrorse, 1.9–7.8 mm; abaxial surface with simple grappling-hook trichomes, adaxial surface with 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. |
|
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, 10.6–17.9 × 5.1–9 mm, apex obtuse, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments oblanceolate, slightly clawed, 6.5–10.5 × 2–4.5 mm, with anthers, second whorl with anthers; anthers twisted or straight after dehiscence, epidermis smooth; styles 6–11.5 mm. |
Capsules | clavate, 12–35 × 2–4 mm, axillary curved to 90° at maturity, usually inconspicuously longitudinally ribbed. |
cup-shaped to cylindric, 6–13.6 × 3.4–6 mm, base tapering to 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 4–9 per cell. |
2n | = 18. |
= 22. |
Mentzelia pectinata |
Mentzelia multicaulis |
|
Phenology | Flowering Mar–May. | Flowering Jun–Aug. |
Habitat | Slopes of sandy or gray-white silty soils, grasslands, oak savannas, uncommonly juniper woodlands. | Sparsely vegetated steep slopes, drainage gullies, roadcuts. |
Elevation | 200–1400 m. (700–4600 ft.) | 2000–2500 m. (6600–8200 ft.) |
Distribution |
CA
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CO
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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.) |
Mentzelia multicaulis is known to occur in Eagle, Grand, and Summit counties. (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 | Touterea multicaulis | |
Name authority | Kellogg: Proc. Calif. Acad. Sci. 3: 40, fig. 9. (1863) | (Osterhout) J. Darlington: Ann. Missouri Bot. Gard. 21: 156. (1934) |
Web links |