Mentzelia mollis |
Mentzelia packardiae |
|
---|---|---|
smooth blazingstar, smooth stick-leaf, soft blazingstar |
Packard's blazingstar, Packard's mentzelia, Packard's stick-leaf |
|
Habit | Plants candelabra-form, 3–15(–20) cm. | Plants candelabra-form, (10–)20–45 cm. |
Basal leaves | not persisting. |
persisting or not. |
Cauline leaves | petiole present (proximal leaves), absent (distal leaves); blade lanceolate to linear (proximal leaves), ovate to lanceolate (distal leaves), to 6 cm, margins dentate or entire (proximal leaves), entire (distal leaves). |
petiole present or absent (proximal leaves), absent (distal leaves); blade lanceolate to linear (proximal leaves), ovate to linear (distal leaves), to 10(–14) cm, margins dentate or entire (proximal leaves), entire (distal leaves). |
Bracts | green, ovate to elliptic, 5–8.5 × 2–5 mm, width 2/5–3/5 length, not concealing capsule, margins entire. |
green, ovate to elliptic, 4.3–8.3 × 1.9–3.2 mm, width 1/3–2/3 length, not concealing capsule, margins entire. |
Flowers | sepals 3–5.5 mm; petals yellow to orange proximally, yellow distally, 8–12 mm, apex rounded; stamens 20+, 3–8 mm, filaments monomorphic, filiform, unlobed; styles 7–9 mm. |
sepals 4–10 mm; petals orange proximally, yellow distally, 10–20 mm, apex rounded to retuse; stamens 20+, 4–13 mm, filaments monomorphic, filiform, unlobed; styles 6–14 mm. |
Capsules | cylindric or clavate, 5–22 × 2–4 mm, axillary curved to 45° at maturity, often prominently longitudinally ribbed. |
narrow-cylindric, 8–35 × 2.5–4 mm, axillary curved to 45° at maturity, often prominently longitudinally ribbed. |
Seeds | 15–25, in 2+ rows distal to mid fruit, tan, dark-mottled, irregularly polygonal, surface smooth to minutely tessellate under 10x magnification; recurved flap over hilum absent; seed coat cell outer periclinal wall flat to slightly convex. |
10–20, in 1 row distal to mid fruit, tan, dark-mottled or not, triangular prisms, surface ±smooth to minutely tessellate under 10x magnification; recurved flap over hilum absent; seed coat cell outer periclinal wall flat to slightly convex. |
2n | = 36. |
= 72. |
Mentzelia mollis |
Mentzelia packardiae |
|
Phenology | Flowering Apr–Jul. | Flowering May–Jul. |
Habitat | Barren, sodic or calcic clay slopes and bluffs derived from volcanic ash. | Yellow to whitish green ash-tuff soils, coarse gravels, steep, open to grassy slopes. |
Elevation | 800–1500 m. (2600–4900 ft.) | 800–1300(–2000) m. (2600–4300(–6600) ft.) |
Distribution |
ID; NV; OR
|
OR
|
Discussion | Mentzelia mollis is narrowly distributed in eastern Malheur County, Oregon, and western Owyhee County, Idaho, and disjunctly in the Black Rock Range of Humboldt County, Nevada. Recent phylogenetic studies support treatment of these disjunct populations as a single species (J. M. Brokaw and L. Hufford 2010b). In both ranges, M. mollis is predominantly limited to barren soils with high salinity. Mentzelia mollis is listed as endangered by the Oregon Department of Agriculture and is in the Center for Plant Conservation’s National Collection of Endangered Plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Mentzelia packardiae is the most narrowly distributed species in sect. Trachyphytum, known only from the Leslie Gulch area in eastern Malheur County. During most years, M. packardiae is predominantly limited to barren, ash-derived gravel slopes. A reported collection from Elko County, Nevada, is most likely from a large-flowered population of M. dispersa (N. H. Holmgren et al. 2005). Mentzelia packardiae can be distinguished from M. dispersa by its larger flowers with longer petals [10–20 mm versus 2–6(–8) mm] and styles [6–14 mm versus 2–3.5(–5) mm], and its wider capsules (2.5–4 mm versus 1–2.5 mm). Mentzelia packardiae is listed as threatened by the Oregon Department of Agriculture and is in the Center for Plant Conservation’s National Collection of Endangered Plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 539. | FNA vol. 12, p. 541. |
Parent taxa | Loasaceae > Mentzelia > sect. Trachyphytum | Loasaceae > Mentzelia > sect. Trachyphytum |
Sibling taxa | ||
Name authority | M. Peck: Leafl. W. Bot. 4: 183. (1945) | Glad: Madroño 23: 289, figs. 2C,D. (1976) |
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