Mentzelia packardiae |
Mentzelia memorabilis |
|
---|---|---|
Packard's blazingstar, Packard's mentzelia, Packard's stick-leaf |
nine-eleven blazingstar, september 11 stickleaf |
|
Habit | Plants candelabra-form, (10–)20–45 cm. | Plants perennial, bushlike, with subterranean caudices. |
Stems | multiple, erect, straight; branches distal, distal longest, antrorse, straight; hairy. |
|
Leaves | blade 17–36.6 × 1.1–4.8 mm, widest intersinus distance 1.1–4.8 mm; proximal linear to oblanceolate, margins entire; distal linear, base not clasping, margins entire; abaxial surface with simple grappling-hook, complex grappling-hook, and needlelike trichomes, adaxial surface with simple grappling-hook and needlelike trichomes. |
|
Basal leaves | persisting or not. |
|
Cauline 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, 4.3–8.3 × 1.9–3.2 mm, width 1/3–2/3 length, not concealing capsule, margins entire. |
margins entire. |
Flowers | 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. |
petals golden yellow, 7.4–11 × 2.6–3.4 mm, apex rounded, glabrous abaxially; stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 5.5–9.1 × 1.4–2.7 mm, with anthers, second whorl with anthers; anthers twisted or straight after dehiscence, epidermis smooth; styles 4.8–8 mm. |
Capsules | narrow-cylindric, 8–35 × 2.5–4 mm, axillary curved to 45° at maturity, often prominently longitudinally ribbed. |
cup-shaped, 3.6–5.3 × 3.1–4.2 mm, base rounded, not longitudinally ridged. |
Seeds | 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. |
coat anticlinal cell walls straight, papillae 6–10 per cell. |
2n | = 72. |
|
Mentzelia packardiae |
Mentzelia memorabilis |
|
Phenology | Flowering May–Jul. | Flowering Jun–Sep. |
Habitat | Yellow to whitish green ash-tuff soils, coarse gravels, steep, open to grassy slopes. | Barren gypsum-clay outcrops and hilltops. |
Elevation | 800–1300(–2000) m. (2600–4300(–6600) ft.) | 1400–1700 m. (4600–5600 ft.) |
Distribution |
OR
|
AZ |
Discussion | 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.) |
Mentzelia memorabilis occurs on the Uinkaret Plateau in Mohave County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 541. | FNA vol. 12, p. 512. |
Parent taxa | Loasaceae > Mentzelia > sect. Trachyphytum | Loasaceae > Mentzelia > sect. Bartonia |
Sibling taxa | ||
Name authority | Glad: Madroño 23: 289, figs. 2C,D. (1976) | N. H. Holmgren & P. K. Holmgren: Syst. Bot. 27: 753, fig. 4. (2002) — (as memorabalis) |
Web links |