Eriogonum maculatum |
Eriogonum crosbyae |
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angle stermed buckwheat, spotted buckwheat, spotted wild buckwheat |
Crosby's buckwheat, Crosby's wild buckwheat |
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Habit | Herbs, erect to spreading, annual, 1–2(–3) dm, tomentose, greenish to reddish. | Herbs, matted, scapose, 0.05–1.5(–2) × (0.1–)1–3 dm, floccose to tomentose or glabrous, sometimes glandular, greenish or grayish. |
Stems | caudex absent; aerial flowering stems erect, not striated or angled, solid, not fistulose, 0.1–0.5 dm, tomentose. |
matted, with persistent leaf bases, up to 1/5 height of plant; caudex stems matted; aerial flowering stems scapelike, weakly erect to erect, slender, solid, not fistulose, 0.02–1.5(–1.8) dm, floccose to tomentose or glabrous, occasionally also or only sparsely to densely glandular. |
Leaves | basal and cauline; basal: petiole 0.3–1 cm, floccose, blade lanceolate to obovate, 1–3(–4) × 1–1.5(–2) cm, tomentose abaxially, sparsely floccose to glabrate and grayish to greenish adaxially, margins entire or infrequently crenulate; cauline sessile, blade lanceolate to oblanceolate, 0.5–2 × 0.3–1 cm, similar to basal blade. |
basal, fasciculate in terminal tufts; petiole 0.2–3(–3.5) cm, tomentose, infrequently glandular; blade oblanceolate to spatulate or elliptic to obovate or ovate, (0.5–)1–2(–3) × 0.2–1(–1.5) cm, densely white- or grayish-tomentose on both surfaces, sometimes less and greenish white adaxially, margins plane. |
Inflorescences | cymose, open, 5–25 × 10–30 cm; branches tomentose; bracts 3, scalelike, 0.5–2.5 × 1–2 mm. |
capitate, 0.7–1.5 cm; branches absent; bracts 3, narrowly triangular to triangular, scalelike, 1–3 mm. |
Peduncles | spreading, straight or nearly so, filiform, (0.5–)1–3 cm, glandular-puberulent. |
absent. |
Involucres | campanulate, 1–1.5(–2) × 1.5–3(–3.5) mm, glandular-puberulent; teeth 5, erect, 0.4–0.8 mm. |
(3–)5–8 per cluster, turbinate to campanulate, (1.5–)2–5(–5.5) × 2–4(–4.5) mm, rigid or membranous, tomentose to floccose, occasionally glabrous except for floccose teeth, rarely sparsely pilose and glandular; teeth 5–7, erect to spreading or reflexed, 0.5–1.5 mm. |
Flowers | 1–2.5 mm; perianth white to yellow, becoming pink or red, with a conspicuous rose-purple spot on each outer tepal, glandular-puberulent; tepals dimorphic, those of outer whorl elliptic to roundish or obovate, inflated from base to middle, those of inner whorl lanceolate; stamens included, 1–1.5(–2) mm; filaments pilose proximally. |
1.5–3.5(–4) mm, glabrous or occasionally minutely glandular, pustulose in some; perianth yellow to pale yellow or, rarely, cream; tepals connate proximal 1/4–1/3, monomorphic, oblong to oblong-obovate; stamens exserted, 1.5–4 mm; filaments glabrous or sparsely pilose proximally. |
Achenes | brown, 3-gonous, 1–1.5 mm, glabrous. |
light brown, 2–4 mm, glabrous or sometimes with minute bristles on beak. |
2n | = 40. |
= 40. |
Eriogonum maculatum |
Eriogonum crosbyae |
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Phenology | Flowering Apr–Nov. | Flowering May–Aug. |
Habitat | Sandy to gravelly or clayey flats and slopes, mixed grassland, saltbush, creosote bush, and sagebrush communities, pinyon-juniper and montane conifer woodlands | White tuffaceous shale volcanic outcrops, metamorphic rock outcrops, or basaltic or granitic sandy flats, washes, slopes, and ridges, saltbush and sagebrush or high-elevation sagebrush to alpine tundra communities, juniper or montane conifer woodlands |
Elevation | 100-2500 m (300-8200 ft) | (1200-)1400-3100 |
Distribution |
AZ; CA; ID; NM; NV; OR; UT; WA; Mexico (Baja California)
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ID; MT; NV; OR
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Discussion | Eriogonum maculatum is the most common and widespread expression of the E. angulosum complex, being found in Arizona, California, southwestern Idaho, Nevada, northwestern New Mexico, eastern Oregon, western Utah, and southeastern Washington. It is often common to abundant and may even be weedy, especially along roadsides intermixed with other annual wild buckwheats. The swollen bases of the outer tepals readily distinguish the species. The greatest concentrations of the spotted wild buckwheat are found in the Mojave Desert and the Great Basin. A specimen supposedly found on the “Laramie Plains” of Wyoming (Parry s.n., 1882, ISC) is discounted as to location. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Eriogonum crosbyae, as now defined, is widely scattered in the valley bottoms and foothills, and atop several mountain ranges of central Idaho (Blaine, Butte, Camas, Custer, and Lemhi counties) and in western Montana (Deer Lodge and Ravalli counties). It is disjunct to southwestern Idaho (Owyhee Mountains, Owyhee County), southeastern Oregon (Guano and Coleman valleys, Harney County, and Fish Fin Rim, Lake County), and in northwestern Nevada (Washoe and Humboldt counties south through Douglas, Lyon, and Pershing counties to Mineral County). It also occus in the Marys River Peak area of Elko County, Nevada. The species may be subdivided into four phases, for which names are available. The vast majority of populations have bright yellow flowers with pustulose bases and midveins. The pustulose condition may also be observed in Eriogonum chrysops (on pale greenish-yellow flowers) and in E. mancum (with cream-colored flowers). Populations with pale yellow flowers here assigned to E. crosbyae occur in the mountains near Mackay, Idaho, and cream-colored flowers are found near Challis and around Salmon, both well outside the known ranges of E. chrysops and E. mancum. Final resolution of the taxonomy of this group awaits further study. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 411. | FNA vol. 5, p. 277. |
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla |
Sibling taxa | ||
Synonyms | E. angulosum subsp. maculatum, E. angulosum var. maculatum, E. angulosum var. rectipes | E. capistratum, E. capistratum var. muhlickii, E. capistratum var. welshii, E. meledonum, E. ochrocephalum var. alexanderae, E. verrucosum |
Name authority | A. Heller: Muhlenbergia 2: 188. (1906) | Reveal: Brittonia 33: 442, fig. 1. (1981) |
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