Mentzelia pectinata |
Mentzelia polita |
|
---|---|---|
San Joaquin blazing star |
elegant blazing star, polished blazing star |
|
Habit | Plants candelabra-form, (8–)20–50(–60) cm. | Plants perennial, bushlike, with subterranean caudices. |
Stems | multiple, erect, zigzag or straight; branches along entire stem, distal longest, antrorse, straight to upcurved; glabrescent, smooth to touch. |
|
Leaves | blade 16–84 × 2.2–10.6 mm, widest intersinus distance 2.2–7 mm; proximal oblanceolate, margins usually entire, occasionally dentate, teeth 0–6(–14), perpendicular to leaf axis, 1–2 mm; distal elliptic, lanceolate, or linear, base not clasping, margins usually entire, rarely dentate, teeth 0(–6), perpendicular to leaf axis, 0.6–2 mm; abaxial surface with complex grappling-hook and infrequently needlelike trichomes, adaxial surface with needlelike trichomes. |
|
Basal leaves | persisting; petiole present or absent; blade lanceolate to linear, margins deeply to shallowly lobed. |
|
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 light to golden yellow, 7.8–11(–14.2) × 1.9–2.8(–4.2) mm, apex rounded, glabrous abaxially; stamens white to light yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 5.9–9.2(–10.1) × 1.2–2.7 mm, with anthers, second whorl with anthers; anthers twisted after dehiscence, epidermis smooth; styles 5.2–7.6 mm. |
Capsules | clavate, 12–35 × 2–4 mm, axillary curved to 90° at maturity, usually inconspicuously longitudinally ribbed. |
cup-shaped, 4.5–8.8 × 5.8–8.8 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 15–24 per cell. |
2n | = 18. |
= 22. |
Mentzelia pectinata |
Mentzelia polita |
|
Phenology | Flowering Mar–May. | Flowering Apr–Aug. |
Habitat | Slopes of sandy or gray-white silty soils, grasslands, oak savannas, uncommonly juniper woodlands. | Dry washes, arroyos, steep slopes. |
Elevation | 200–1400 m. (700–4600 ft.) | 500–1500 m. (1600–4900 ft.) |
Distribution |
CA
|
CA; NV |
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 polita is known only from the Clark Mountains of San Bernardino County, California, and the Spring Mountains of Clark County, Nevada. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 541. | FNA vol. 12, p. 512. |
Parent taxa | Loasaceae > Mentzelia > sect. Trachyphytum | Loasaceae > Mentzelia > sect. Bartonia |
Sibling taxa | ||
Name authority | Kellogg: Proc. Calif. Acad. Sci. 3: 40, fig. 9. (1863) | A. Nelson: Bot. Gaz. 47: 427. (1909) |
Web links |