Mentzelia veatchiana |
Mentzelia monoensis |
|
---|---|---|
Veatch's blazing star, white-stem blazingstar, white-stem stick-leaf |
Mono craters blazing star |
|
Habit | Plants candelabra-form, (5–)20–50 cm. | Plants candelabra-form, 10–30 cm. |
Basal leaves | persisting; petiole present or absent; blade linear-lanceolate, margins deeply to shallowly lobed. |
persisting; petiole present or absent; blade linear-lanceolate to linear, margins usually moderately to shallowly lobed, rarely entire. |
Cauline leaves | petiole absent; blade ovate-lanceolate to lanceolate, to 17 cm, margins usually deeply lobed to dentate, rarely entire. |
petiole present or absent (proximal leaves), absent (distal leaves); blade linear-lanceolate to linear (proximal leaves), ovate to linear (distal leaves), to 13 cm, margins usually moderately to shallowly lobed, rarely entire. |
Bracts | usually green with prominent white base usually conspicuously extending outwards from midvein, rarely green, usually ovate, rarely lanceolate, 3.3–6.2 × 1.5–3.2 mm, width 1/4–7/8 length, not concealing capsule, margins usually 3–7-lobed, rarely entire. |
green, sometimes with white base, ovate, 3–4.1 × 1.1–1.7 mm, width 1/4–1/2 length, not concealing capsule, margins entire. |
Flowers | sepals 2–5 mm; petals red to orange proximally, orange to yellow distally, 4–7(–10) mm, apex retuse; stamens 20+, 3–7 mm, filaments monomorphic, filiform, unlobed; styles (3–)3.5–6 mm. |
sepals 2–3 mm; petals orange proximally, yellow distally, 2–4 mm, apex retuse or rounded; stamens 10–30, 2–3 mm, filaments monomorphic, filiform, unlobed; styles 2–3 mm. |
Capsules | clavate, 8–28 × 2–4 mm, axillary curved to 70° at maturity, usually inconspicuously longitudinally ribbed. |
cylindric or clavate, 6–15 × 2–3 mm, axillary curved to 20° at maturity, usually inconspicuously longitudinally ribbed. |
Seeds | 15–35, in 2+ rows distal to mid fruit, tan, dark-mottled, 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 or equal to 1/2 as tall as wide at maturity. |
15–30, in 2+ rows distal to mid fruit, tan, not 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. |
2n | = 54. |
= 54. |
Mentzelia veatchiana |
Mentzelia monoensis |
|
Phenology | Flowering Mar–Jun. | Flowering May–Aug. |
Habitat | Loamy to sandy soils, grasslands, desert scrub, oak-pine woodlands. | Coarse pumice soils on open slopes, sagebrush or bitterbrush scrub, pine forests. |
Elevation | 200–2500 m. [700–8200 ft.] | 2000–2500 m. [6600–8200 ft.] |
Distribution |
AZ; CA; NV; OR
|
CA |
Discussion | Mentzelia veatchiana is the most common and widely distributed hexaploid species in sect. Trachyphytum. It exhibits considerable morphological variation and can be difficult to distinguish from M. montana in northern California. Like the larger-flowered M. pectinata, M. veatchiana has interfertile populations with petal colors ranging from orange to yellow (J. E. Zavortink 1966). When bearing orange petals, M. veatchiana is easily distinguished from other species. Reports of M. veatchiana from Utah are based on specimens treated here as M. montana. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Mentzelia monoensis is narrowly distributed predominantly south of Mono Lake and north of Lake Crowley in Mono County, California, and is most commonly found in soils derived from the eruptions of the Mono Craters (J. M. Brokaw et al. 2015). Phylogenetic studies suggest that this hexaploid is the only allopolyploid derived from representatives of both the “Affines” and “Trachyphyta” clades (Brokaw and L. Hufford 2010b). Mentzelia monoensis is morphologically similar to sympatric populations of M. montana. However, the bracts of M. monoensis are more often unlobed and green throughout. Furthermore, seeds of M. monoensis have tan, unmottled coats that are always composed of cells that are rounded, appearing as shallow domes. In contrast, seeds of M. montana have mottled coats with cells that stand out as rough, pointed knobs along the seed edges. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 543. | FNA vol. 12, p. 539. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | M. albicaulis var. veatchiana | |
Name authority | Kellogg: Proc. Calif. Acad. Sci. 2: 99, fig. 28. (1863) | J. M. Brokaw & L. Hufford: Madroño 58: 57, figs. 1,2A,3. (2011) |
Web links |