Mentzelia decapetala |
Mentzelia packardiae |
|
---|---|---|
10-petal western star, evening starflower, gumbo-lily, tenpetal blazingstar |
Packard's blazingstar, Packard's mentzelia, Packard's stick-leaf |
|
Habit | Plants biennial or perennial, bushlike, perennials with ground-level caudices. | Plants candelabra-form, (10–)20–45 cm. |
Stems | solitary, erect, straight; branches distal or along entire stem, proximal or distal longest, antrorse, straight to upcurved; hairy. |
|
Leaves | blade 72–295 × 14–45 mm, widest intersinus distance 10.1–23.3 mm; proximal oblanceolate or elliptic, margins serrate to pinnate, teeth or lobes 16–26, slightly antrorse, 1–16.5 mm; distal elliptic to lanceolate, base clasping or not, margins serrate to pinnate, teeth or lobes 9–20, slightly antrorse, 5.3–13.7 mm; surfaces with 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 | margins pinnate. |
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 | petals white, 47–75 × 13–22.7 mm, apex acute to attenuate, glabrous abaxially; stamens white to yellow, 5 outermost petaloid, filaments spatulate, strongly clawed, 48–75 × 12–23 mm, without anthers, second whorl with anthers; anthers straight after dehiscence, epidermis smooth; styles 36–53 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, 30–43 × 12–17 mm, base tapering, not longitudinally ridged. |
narrow-cylindric, 8–35 × 2.5–4 mm, axillary curved to 45° at maturity, often prominently longitudinally ribbed. |
Seeds | 2.3–4 mm; coat anticlinal cell walls straight, papillae 4–10 per cell. |
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 | = 22. |
= 72. |
Mentzelia decapetala |
Mentzelia packardiae |
|
Phenology | Flowering Jun–Aug(–Oct). | Flowering May–Jul. |
Habitat | Rock outcrops, slopes, dry short-grass prairies, riverbanks, roadsides, loam, limestone, sandy, silty, clayey, and gravelly soils. | Yellow to whitish green ash-tuff soils, coarse gravels, steep, open to grassy slopes. |
Elevation | 300–2400 m. (1000–7900 ft.) | 800–1300(–2000) m. (2600–4300(–6600) ft.) |
Distribution |
CO; IA; IL; KS; MN; MT; NE; NM; OK; SD; TX; UT; WY; AB; MB; SK
|
OR
|
Discussion | Mentzelia decapetala is introduced in Grundy County, Illinois. It appears to be native throughout the rest of its distribution. (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. 504. | FNA vol. 12, p. 541. |
Parent taxa | Loasaceae > Mentzelia > sect. Bartonia | Loasaceae > Mentzelia > sect. Trachyphytum |
Sibling taxa | ||
Synonyms | Bartonia decapetala | |
Name authority | (Pursh) Urban: Ber. Deutsch. Bot. Ges. 10: 263. (1892) | Glad: Madroño 23: 289, figs. 2C,D. (1976) |
Web links |