Mentzelia pectinata |
Mentzelia laciniata |
|
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San Joaquin blazing star |
cut-leaf blazingstar |
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Habit | Plants candelabra-form, (8–)20–50(–60) cm. | Plants biennial, bushlike or candelabra-form. |
Stems | solitary, erect, straight; branches distal or along entire stem, distal or proximal longest, antrorse, straight; hairy. |
|
Leaves | blade 52–112 × (5.4–)8.3–25 mm, widest intersinus distance 1.4–4 mm; proximal oblanceolate or elliptic, margins pinnatisect, lobes 8–20, slightly antrorse, 4.2–7.4(–10.7) mm; distal oblanceolate, elliptic, or lanceolate, base not clasping, margins usually pinnatisect, sometimes pinnate, especially near apex, lobes 8–18, slightly antrorse, 3–10.8 mm; abaxial surface with simple grappling-hook, complex grappling-hook, and needlelike trichomes, adaxial surface with 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 usually entire, rarely pinnate. |
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, 14–23.8(–26) × 3.8–7.4 mm, apex acute to rounded, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate to elliptic, slightly clawed, 12–20.4 × 2.5–4.9 mm, usually without, rarely with, anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 9.2–17.7 mm. |
Capsules | clavate, 12–35 × 2–4 mm, axillary curved to 90° at maturity, usually inconspicuously longitudinally ribbed. |
cylindric, 12–20.2 × 4.5–8.1 mm, 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 sinuous, papillae 5–14 per cell. |
2n | = 18. |
= 20. |
Mentzelia pectinata |
Mentzelia laciniata |
|
Phenology | Flowering Mar–May. | Flowering Jun–Sep. |
Habitat | Slopes of sandy or gray-white silty soils, grasslands, oak savannas, uncommonly juniper woodlands. | Dry hillsides, roadcuts, roadsides, sandy or clayey soils. |
Elevation | 200–1400 m. (700–4600 ft.) | 1400–2300 m. (4600–7500 ft.) |
Distribution |
CA
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CO; NM |
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 laciniata is found in southwestern Colorado and northwestern New Mexico, where it does not extend as far west as the Chuska Mountains. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 541. | FNA vol. 12, p. 517. |
Parent taxa | Loasaceae > Mentzelia > sect. Trachyphytum | Loasaceae > Mentzelia > sect. Bartonia |
Sibling taxa | ||
Synonyms | Touterea laciniata | |
Name authority | Kellogg: Proc. Calif. Acad. Sci. 3: 40, fig. 9. (1863) | (Rydberg) J. Darlington: Ann. Missouri Bot. Gard. 21: 173. (1934) |
Web links |