Mentzelia albicaulis |
Mentzelia goodrichii |
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small flower blazing star, small-flower evening star, white stem blazing star, white-stem evening star, white-stem stick-leaf |
Goodrich's blazingstar |
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Habit | Plants wandlike or candelabra-form, (2–)10–40(–50) cm. | Plants perennial, bushlike, with subterranean caudices or rhizomes. |
Stems | multiple, erect or decumbent, zigzag or straight; branches along entire stem, distal longest, antrorse, straight; hairy. |
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Leaves | blade 23–35.3 × 6.5–13(–16) mm, widest intersinus distance 3.7–11.3 mm; proximal oblanceolate, margins dentate, teeth 4–10, perpendicular to leaf axis, 0.5–1.8 mm; distal elliptic to lanceolate, base not clasping, margins dentate to pinnate, teeth or lobes 4–8, perpendicular to leaf axis, 1.3–3.6 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 to linear, margins deeply to shallowly lobed. |
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Cauline leaves | petiole absent; blade ovate-lanceolate to linear, to 15 cm, margins deeply to shallowly lobed or entire. |
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Bracts | green, ovate to linear, 3.7–8.6 × 0.8–3.9 mm, width 1/6–2/3 length, not concealing capsule, margins 3-lobed or entire, lateral lobes never prominent. |
margins entire. |
Flowers | sepals 1–5 mm; petals orange proximally, yellow distally, 3–7(–8) mm, apex usually acute, rarely retuse; stamens 20+, 3–5 mm, filaments monomorphic, filiform, unlobed; styles 2–5 mm. |
petals golden yellow, 16.1–18.5 × 6.7–9.2 mm, apex rounded, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 7.8–9.3 × 2.3–3.3 mm, with anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 6.3–8.6 mm. |
Capsules | clavate, 8–28(–35) × 1.5–3.5 mm, longest capsules usually 15+ mm, axillary curved to 180° at maturity, usually inconspicuously longitudinally ribbed. |
cup-shaped, 8–12 × 6–7.2 mm, base rounded, not longitudinally ridged. |
Seeds | 10–30, in 2+ rows distal to mid fruit, dark brown or tan, moderately to densely 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 1/2 as tall as wide at maturity. |
coat anticlinal cell walls straight, papillae 11–15 per cell. |
2n | = 54, 72. |
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Mentzelia albicaulis |
Mentzelia goodrichii |
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Phenology | Flowering Mar–Aug. | Flowering Jul–Aug. |
Habitat | Sand dunes, gravel fans, washes, desert scrub, sagebrush or antelope bitterbrush scrub, open ponderosa pine woodlands, pinyon/juniper woodlands. | Steep slopes composed of Green River Formation shale. |
Elevation | 0–2300 m. (0–7500 ft.) | 1900–2700 m. (6200–8900 ft.) |
Distribution |
AZ; CA; CO; ID; MT; NE; NM; NV; OR; SD; TX; UT; WA; WY; BC; SK; Mexico (Baja California, Chihuahua, Sonora)
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UT |
Discussion | Mentzelia albicaulis is the most widespread species in sect. Trachyphytum and exhibits extensive morphological variation. Most populations of M. albicaulis are octoploid; however, hexaploids from southern California that have been called M. mojavensis and occasionally M. californica are also treated here as M. albicaulis. Two tetraploids in sect. Trachyphytum, M. montana and M. obscura, also have been treated previously as M. albicaulis (N. H. Holmgren et al. 2005). Both exhibit morphological forms and distributions overlapping with M. albicaulis. However, in most cases these species can be distinguished without chromosome counts, and their distinctiveness has been supported by phylogenetic analyses (J. M. Brokaw and L. Hufford 2010b). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Mentzelia goodrichii is known only from Duchesne County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 534. | FNA vol. 12, p. 513. |
Parent taxa | Loasaceae > Mentzelia > sect. Trachyphytum | Loasaceae > Mentzelia > sect. Bartonia |
Sibling taxa | ||
Synonyms | Bartonia albicaulis, M. mojavensis | |
Name authority | (Douglas) Douglas ex Torrey & A. Gray: Fl. N. Amer. 1: 534. (1840) | K. H. Thorne & S. L. Welsh: Rhodora 95: 407, fig. 14. (1993) |
Web links |