Mentzelia obscura |
Mentzelia lindleyi |
|
---|---|---|
Pacific blazing star |
Lindley's blazing star |
|
Habit | Plants candelabra-form, 8–45 cm. | Plants candelabra-form, 30–70 cm. |
Basal leaves | persisting; petiole present or absent; blade linear-lanceolate to linear, margins usually irregularly deeply lobed, lobes pointed. |
persisting; petiole present or absent; blade lanceolate to linear, margins usually deeply lobed, lobes rounded. |
Cauline leaves | petiole absent; blade ovate-lanceolate to linear, to 15(–22) cm, margins few-lobed or entire. |
petiole absent; blade ovate to lanceolate, to 17 cm, margins deeply to shallowly lobed. |
Bracts | green, ovate to ovate-lanceolate, 2.9–8.2 × 1.1–1.9 mm, width 1/8–1/2 length, not concealing capsule, margins entire. |
green, ovate to lanceolate, 6.1–14.2 × 3.6–5.1 mm, width 1/3–2/3 length, not concealing capsule, margins 3–7-lobed. |
Flowers | sepals 2–6 mm; petals yellow to orange proximally, yellow distally, 3–8 mm, apex rounded or acute apex; stamens 20–40, 2–7 mm, filaments monomorphic, filiform, unlobed; styles 2–6 mm. |
sepals 9–19 mm; petals orange proximally, yellow distally, obovate, 20–40 × (12–)16–33 mm, apex mucronate; stamens 20+, 12–30 mm, filaments heteromorphic, 5 outermost linear, inner filiform, unlobed; styles 15–24 mm. |
Capsules | clavate, 11–31 × 1.5–3 mm, axillary curved to 250° at maturity, usually inconspicuously longitudinally ribbed. |
clavate, 25–40 × 4–5 mm, axillary curved to 90° at maturity, usually inconspicuously longitudinally ribbed. |
Seeds | 15–50, in 2+ rows distal to mid fruit, tan, usually not, occasionally sparsely, dark-mottled, usually irregularly polygonal, occasionally triangular prisms proximal to mid fruit, surface colliculate under 10x magnification; recurved flap over hilum absent; seed coat cell outer periclinal wall domed, domes on seed edges less than 1/2 as tall as wide at maturity. |
30–40, in 2+ rows distal to mid fruit, tan, dark-mottled or not, irregularly polygonal, surface minutely tessellate under 10x magnification; recurved flap over hilum absent; seed coat cell outer periclinal wall domed, domes on seed edges less than 1/2 as tall as wide at maturity. |
2n | = 36. |
= 36. |
Mentzelia obscura |
Mentzelia lindleyi |
|
Phenology | Flowering Feb–May. | Flowering May–Jun. |
Habitat | Sandy to rocky washes or slopes, desert scrub, Joshua-tree woodlands, roadsides. | Rocky, open slopes, coastal sage scrub, oak-pine woodlands. |
Elevation | 200–1700 m. (700–5600 ft.) | 90–1400 m. (300–4600 ft.) |
Distribution |
AZ; CA; NV; UT; Mexico (Baja California, Sonora)
|
CA
|
Discussion | Mentzelia obscura is morphologically intermediate to M. desertorum and M. albicaulis and is known to occur in mixed populations with both species. Reliable discrimination among these species usually requires mature seeds. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Naturally occurring populations of Mentzelia lindleyi are limited primarily to the Coast Ranges of the San Francisco Bay area. However, commercial distribution of seeds has resulted in casual alien populations of M. lindleyi throughout the southwestern United States. See 68. M. crocea for discussion of similarities between these species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 540. | FNA vol. 12, p. 538. |
Parent taxa | Loasaceae > Mentzelia > sect. Trachyphytum | Loasaceae > Mentzelia > sect. Trachyphytum |
Sibling taxa | ||
Synonyms | Bartonia aurea | |
Name authority | H. J. Thompson & J. E. Roberts: Phytologia 21: 284. (1971) | Torrey & A. Gray: Fl. N. Amer. 1: 533. (1840) |
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