Mentzelia veatchiana |
Mentzelia asperula |
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Veatch's blazing star, white-stem blazingstar, white-stem stick-leaf |
mountain stickleaf, Organ Mountain blazingstar |
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Habit | Plants candelabra-form, (5–)20–50 cm. | Plants annual, without caudices or tubers. |
Stems | erect, to 25 cm. |
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Leaves | petiole to 12 mm (proximal leaves), absent (distal leaves); blade usually ovate to hastate, or smallest distal elliptic or lanceolate, basally lobed or unlobed, to 4.5 × 3.5 cm, base cuneate or obtuse to truncate, margins serrate, apex acute. |
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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. |
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Pedicels | (fruiting) 1–3 × 2 mm. |
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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 orange, 5–8 × 3–5 mm, apex cuspidate, hairy abaxially at apex; stamens 10–20, 5–8 mm, filaments monomorphic, filiform; style 3–5 mm. |
Capsules | clavate, 8–28 × 2–4 mm, axillary curved to 70° at maturity, usually inconspicuously longitudinally ribbed. |
subcylindric to clavate, 12–25 × 3–5 mm, base tapering gradually, capsule and pedicel not well-differentiated. |
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. |
(7–)8–10(–12) per capsule, pyriform, without transverse folds. |
2n | = 54. |
= 20, 40. |
Mentzelia veatchiana |
Mentzelia asperula |
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Phenology | Flowering Mar–Jun. | Flowering Aug–Oct. |
Habitat | Loamy to sandy soils, grasslands, desert scrub, oak-pine woodlands. | Rocky limestone or igneous slopes, arroyo bottoms, grasslands, oak woodlands. |
Elevation | 200–2500 m. [700–8200 ft.] | 0–1800 m. [0–5900 ft.] |
Distribution |
AZ; CA; NV; OR
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AZ; NM; TX; n Mexico; c Mexico
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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.) |
Populations consistent with the form and geographic region of the type specimen of Mentzelia asperula (collected in southwestern New Mexico) have been recovered in two clades of sect. Mentzelia. In one clade, M. asperula is closely related to M. isolata; in the second clade, it is closely related to M. gypsophila B. L. Turner of northern Mexico (J. Grissom 2014). The polyphyly of M. asperula likely represents convergence on rapid developmental times and small, self-fertilizing flowers. In southeastern Arizona, M. asperula can be difficult to distinguish from M. isolata; see the discussion of the latter for more information. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 543. | FNA vol. 12, p. 528. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | M. albicaulis var. veatchiana | |
Name authority | Kellogg: Proc. Calif. Acad. Sci. 2: 99, fig. 28. (1863) | Wooton & Standley: Contr. U.S. Natl. Herb. 16: 148. (1913) |
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