Mentzelia veatchiana |
Mentzelia collomiae |
|
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Veatch's blazing star, white-stem blazingstar, white-stem stick-leaf |
Sunset Crater blazingstar |
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Habit | Plants candelabra-form, (5–)20–50 cm. | Plants biennial, candelabra-form. |
Stems | solitary, erect, straight; branches distal, distal longest, antrorse, straight; hairy. |
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Leaves | blade 17.8–55.2 × 3–16.6(–26.3) mm, widest intersinus distance 1.4–4.9 mm; proximal oblanceolate, lanceolate, or elliptic, margins dentate to pinnate, teeth or lobes 8–18, perpendicular to leaf axis, 0.6–5.3 mm; distal elliptic to lanceolate, base not clasping, margins dentate to pinnate, teeth or lobes 4–12, perpendicular to leaf axis, 0.7–6.8 mm; abaxial surface with simple grappling-hook, complex grappling-hook, and needlelike trichomes, adaxial surface with simple grappling-hook and needlelike trichomes. |
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Basal leaves | persisting; petiole present or absent; blade linear-lanceolate, margins deeply to shallowly lobed. |
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Cauline leaves | petiole absent; blade ovate-lanceolate to lanceolate, to 17 cm, margins usually deeply lobed to dentate, rarely entire. |
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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. |
margins usually entire, occasionally toothed. |
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. |
petals golden yellow, 8.5–16.2 × 2.6–6.4 mm, apex acute to rounded, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, strongly clawed, (6–)9.9–13.8 × (1–)2.4–4.3 mm, without anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles (5–)7.8–11 mm. |
Capsules | clavate, 8–28 × 2–4 mm, axillary curved to 70° at maturity, usually inconspicuously longitudinally ribbed. |
cylindric, 9.3–16.1 × 3.6–5.9 mm, base tapering, not longitudinally ridged. |
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. |
coat anticlinal cell walls sinuous, papillae 51–59 per cell. |
2n | = 54. |
= 22. |
Mentzelia veatchiana |
Mentzelia collomiae |
|
Phenology | Flowering Mar–Jun. | Flowering Jun–Aug. |
Habitat | Loamy to sandy soils, grasslands, desert scrub, oak-pine woodlands. | Sparsely vegetated level ground, slopes, black (to sometimes reddish) volcanic cinder cone soils. |
Elevation | 200–2500 m. [700–8200 ft.] | 1300–2500 m. [4300–8200 ft.] |
Distribution |
AZ; CA; NV; OR
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AZ |
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 collomiae is known only from the San Francisco Volcanic Field of Coconino County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 543. | FNA vol. 12, p. 519. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | M. albicaulis var. veatchiana | |
Name authority | Kellogg: Proc. Calif. Acad. Sci. 2: 99, fig. 28. (1863) | Christy: Novon 7: 25. (1997) |
Web links |