Mentzelia veatchiana |
Mentzelia multiflora |
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Veatch's blazing star, white-stem blazingstar, white-stem stick-leaf |
Adonis blazingstar, Adonis stickleaf, desert stickleaf, many-flower western star |
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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, upcurved; hairy. |
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Leaves | blade 35.9–125(–146) × 2.2–26.2 mm, widest intersinus distance 2.1–11.9(–14) mm, always on some leaves 4+ mm; proximal oblanceolate, lanceolate, or elliptic, margins pinnate, lobes 14–30, slightly antrorse or perpendicular to leaf axis, 1.5–4.6(–8.9) mm; distal lanceolate, base not clasping, margins pinnate, lobes 10–26, slightly antrorse or perpendicular to leaf axis, 1.3–9.5 mm; abaxial surface with simple grappling-hook, complex grappling-hook, and generally needlelike trichomes, adaxial surface with simple grappling-hook or 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 entire or toothed to pinnate. |
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 light to golden yellow, (11.4–)13.8–24.4(–26.9) × 4–7.5 mm, apex rounded, glabrous abaxially; stamens light to golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, (10.6–)12–21.7 × 2.1–5.1 mm, without anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 7.7–15.8 mm. |
Capsules | clavate, 8–28 × 2–4 mm, axillary curved to 70° at maturity, usually inconspicuously longitudinally ribbed. |
cylindric, 11.2–24.7 × 5.6–8.7 mm, base tapering to rounded, 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 34–48 per cell. |
2n | = 54. |
= 18. |
Mentzelia veatchiana |
Mentzelia multiflora |
|
Phenology | Flowering Mar–Jun. | Flowering Jul–Sep. |
Habitat | Loamy to sandy soils, grasslands, desert scrub, oak-pine woodlands. | Dry roadsides, hillsides, washes, clayey, rocky, or sandy soils. |
Elevation | 200–2500 m. [700–8200 ft.] | 1200–2100 m. [3900–6900 ft.] |
Distribution |
AZ; CA; NV; OR
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CO; NE; NM; WY
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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.) |
Mentzelia multiflora has been considered one of the most widespread species in sect. Bartonia, a result of treating the species as a "garbage bin" for populations that lack features characteristic of more specialized species. The phylogenetic study by J. J. Schenk and L. Hufford (2011) showed that populations consistent with the type of M. multiflora are centered in the southern Rocky Mountains, especially along their eastern front, and the species notably does not occur in Arizona, California, Nevada, or Utah, in which it regularly has been described in regional floras. In the intermountain region, many specimens previously determined as M. multiflora are M. longiloba. In southeastern New Mexico and Texas, many specimens previously determined as M. multiflora are likely to be M. procera or M. longiloba var. chihuahuaensis. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 543. | FNA vol. 12, p. 523. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | M. albicaulis var. veatchiana | Bartonia multiflora, M. lutea, Nuttallia multiflora |
Name authority | Kellogg: Proc. Calif. Acad. Sci. 2: 99, fig. 28. (1863) | (Nuttall) A. Gray: Mem. Amer. Acad. Arts, n. s. 4: 48. (1849) |
Web links |