Mentzelia dispersa |
Mentzelia multicaulis |
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bushy blazing-star, bushy mentzelia, Nada stickleaf, Nevada blazingstar, scattered blazing star |
manystem blazingstar, multiple-branch blazingstar |
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Habit | Plants wandlike or candelabra-form, 10–40(–50) cm. | Plants perennial, bushlike, with subterranean caudices or sometimes rhizomes. |
Stems | multiple, erect or decumbent, zigzag or straight; branches distal or along entire stem, distal longest or all ± equal, antrorse, straight to upcurved; hairy. |
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Leaves | blade 20–49(–57) × 4.2–19 mm, widest intersinus distance 1.1–5.3 mm; proximal oblanceolate to elliptic, margins pinnate to pinnatisect, lobes 4–10, slightly antrorse, 0.7–7.6 mm; distal linear to lanceolate, base not clasping, margins entire or pinnate, lobes 0–10, slightly antrorse, 1.9–7.8 mm; abaxial surface with simple grappling-hook trichomes, adaxial surface with grappling-hook and needlelike trichomes. |
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Basal leaves | persisting; petiole present or absent; blade elliptic to linear, margins usually dentate, sinuses extending less than 1/4 to midvein, or entire, rarely deeply lobed. |
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Cauline leaves | petiole present or absent (proximal leaves), absent (distal leaves); blade elliptic to linear (proximal leaves), orbiculate to linear (distal leaves), to 10 cm, margins usually dentate, sinuses extending less than 1/4 to midvein, or entire, rarely deeply lobed. |
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Bracts | green, orbiculate to ovate, 2.1–6.5 × 1.1–3 mm, width 1/3–7/8 length, not concealing capsule, margins 3-lobed or entire. |
margins entire. |
Flowers | sepals 1–3.5 mm; petals usually yellow, rarely orange, proximally, yellow distally, 2–6(–8) mm, apex rounded; stamens 20–40, 2–4.5 mm, filaments monomorphic, filiform, unlobed; styles 2–3.5(–5) mm. |
petals golden yellow, 10.6–17.9 × 5.1–9 mm, apex obtuse, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments oblanceolate, slightly clawed, 6.5–10.5 × 2–4.5 mm, with anthers, second whorl with anthers; anthers twisted or straight after dehiscence, epidermis smooth; styles 6–11.5 mm. |
Capsules | narrow-cylindric, 7–30 × 1–2.5 mm, axillary curved to 30° at maturity, usually inconspicuously longitudinally ribbed. |
cup-shaped to cylindric, 6–13.6 × 3.4–6 mm, base tapering to rounded, not longitudinally ridged. |
Seeds | 10–20, in 1 row distal to mid fruit, tan, dark-mottled or not, triangular prisms, surface ± smooth under 10x magnification; recurved flap over hilum absent; seed coat cell outer periclinal wall flat. |
coat anticlinal cell walls straight, papillae 4–9 per cell. |
2n | = 18, 36, 72. |
= 22. |
Mentzelia dispersa |
Mentzelia multicaulis |
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Phenology | Flowering (Apr–)May–Aug(–Sep). | Flowering Jun–Aug. |
Habitat | Loamy to sandy or rocky slopes, grasslands, scrub, dry forests, roadsides. | Sparsely vegetated steep slopes, drainage gullies, roadcuts. |
Elevation | 400–3100 m. (1300–10200 ft.) | 2000–2500 m. (6600–8200 ft.) |
Distribution |
AZ; CA; CO; ID; MT; ND; NV; OR; SD; UT; WA; WY; BC
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CO
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Discussion | Mentzelia dispersa is the only polyploid species solely derived from the “Affines” clade and may be an autopolyploid complex (J. M. Brokaw and L. Hufford 2010, 2010b). Morphological characters that consistently distinguish cytotypes within M. dispersa have not been found. Mentzelia dispersa is most easily confused with M. affinis (see discussion under 65. M. affinis) but is phylogenetically distinct (Brokaw and Hufford 2010, 2010b). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Mentzelia multicaulis is known to occur in Eagle, Grand, and Summit counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 536. | FNA vol. 12, p. 511. |
Parent taxa | Loasaceae > Mentzelia > sect. Trachyphytum | Loasaceae > Mentzelia > sect. Bartonia |
Sibling taxa | ||
Synonyms | M. albicaulis var. integrifolia, M. dispersa var. compacta, M. dispersa var. latifolia, M. dispersa var. obtusa, M. pinetorum | Touterea multicaulis |
Name authority | S. Watson: Proc. Amer. Acad. Arts 11: 137. (1876) | (Osterhout) J. Darlington: Ann. Missouri Bot. Gard. 21: 156. (1934) |
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