Eriogonum rotundifolium |
Eriogonum latifolium |
|
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round-leaf wild buckwheat, roundleaf buckwheat |
coast buckwheat, coast wild buckwheat, seaside buckwheat, seaside wild buckwheat |
|
Habit | Herbs, spreading, annual, 0.5–4 dm, glabrous and often glaucous, greenish to grayish. | Subshrubs or herbs, often scapose, much-branched and matted, 2–7 × 5–20 dm, usually tomentose to floccose, rarely glabrous. |
Stems | caudex absent; aerial flowering stems erect, solid, not fistulose, 0.1–0.5(–0.7) dm, glabrous. |
spreading to erect, with persistent leaf bases, up to 1/4 height of plant; caudex stems matted; aerial flowering stems often scapelike, erect to spreading or decumbent, usually stout, solid, not fistulose, 2–6 dm, usually tomentose to floccose, rarely glabrous. |
Leaves | basal; petiole 1.5–4 cm, floccose; blade cordate to orbiculate, 1–2(–3) × 1–2.5(–3) cm, densely white-tomentose abaxially, floccose or subglabrous and greenish adaxially, margins plane. |
cauline; petiole 2–6(–10) cm, tomentose; blade oblong to ovate, (1.5–)2.5–5 × 1.5–4 cm, white-lanate to tawny-tomentose on both surfaces, or tomentose to floccose or glabrous and green adaxially, margins plane, occasionally crisped. |
Inflorescences | cymose, open to diffuse, usually flat-topped, 5–35 × 5–35 cm; branches glabrous; bracts 3, scalelike, 1–2.5 × 0.5–2 mm. |
capitate to umbellate or cymose, 3–40 × 2–20 cm; branches usually tomentose to floccose, rarely glabrous; bracts usually 3, leaflike, oblong to ovate, and 5–20 × 5–15 mm proximally, scalelike, triangular, and 2–5 mm distally. |
Peduncles | erect, straight, stoutish, 0.3–1.5 cm, glabrous. |
absent. |
Involucres | turbinate to campanulate, 1–2 × 1.5–2.5 mm, glabrous; teeth 5, erect, 0.4–0.8 mm. |
(3–)5–20 per cluster, turbinate, 3.5–5(–6) × 2–4 mm, tomentose or glabrous; teeth 5–6, erect, 0.3–0.6 mm. |
Flowers | 1–2.5 mm; perianth white to pink with greenish to reddish midribs, becoming rose to red, glabrous; tepals dimorphic, those of outer whorl flabellate, those of inner whorl lanceolate; stamens included, 1.2–1.7 mm; filaments pilose proximally. |
3–3.5 mm; perianth white to pink or rose, glabrous; tepals connate proximal 1/4, monomorphic, obovate; stamens exserted, 3–6 mm; filaments pilose proximally. |
Achenes | dark brown, 3-gonous, 1.5–2 mm, glabrous. |
brown, 3.5–4 mm, glabrous. |
2n | = 40. |
= 40. |
Eriogonum rotundifolium |
Eriogonum latifolium |
|
Phenology | Flowering May–Oct. | Flowering year-round. |
Habitat | Sandy to gravelly flats and slopes, mixed grassland, saltbush, creosote bush, and mesquite communities, juniper woodlands | Sandy coastal flats, slopes, bluffs, and mesas, coastal scrub and grassland communities |
Elevation | 600-1800 m (2000-5900 ft) | 0-80(-200) m (0-300(-700) ft) |
Distribution |
AZ; NM; TX; Mexico (Chihuahua, Coahuila)
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CA; OR
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Discussion | Eriogonum rotundifolium is the southern counterpart to E. cernuum, being common to abundant and occasionally even weedy. Its overall range, however, is significantly smaller. It occurs in Arizona only in Cochise County, but is found more widely in New Mexico, and is common in the trans-Pecos region of western Texas, with scattered populations in Dimmit, Ector, Foard, and Knox counties outside that region. A sterile Edwin James specimen gathered in 1820 (NY) supposedly was collected near the Rocky Mountains and may be Eriogonum rotundifolium. Also seen at NY is an unattributed, redistributed collection of this species labeled only “Colorado.” Until better documented material from that state is seen, the species is considered not to be a member of the Colorado flora. F. A. Elmore (1943) reported that the round-leaf wild buckwheat was used by the Navajo (Diné) people as an emetic. My own consumption of a few seeds, as a self-experiment, produced no particular urge to vomit. Inasmuch as the treatment was taken after swallowing ants, it is difficult to know whether the ants or the seeds were the emetic. G. M. Hocking (1956) reported that the leaves were used for sore throats and the stems were eaten raw (the latter proving in the same self-experiment not to be particularly tasty, leaving a slightly sour aftertaste). Hocking also reported that the roots were used medicinally but mentioned no specific ailment. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Eriogonum latifolium is found along the immediate coast of southwest Oregon (Curry County) and western California (Alameda, Contra Costa, Del Norte, Humboldt, Marin, Mendocino, Monterey, San Francisco, San Luis Obispo, San Mateo, Santa Cruz, and Sonoma counties). The species is rather variable as to size and aspect, these depending to a considerable degree on exposure to on-shore winds. The flowering stems are rarely glabrous, but plants with this expression are always intermixed with plants having tomentose to floccose stems. The brilliantly white-lanate, spreading shrubs become rather globose in shape under cultivation, and as a result make an attractive addition to the garden, especially as the flowers wither through various shades of pink to rose. The species should be used much more than at present in places where cool summer temperatures, good moisture, and sandy soils are available. A decoction consisting of the roots, leaves, and stems of Eriogonum latifolium was taken by various Native American people along the California coast for colds and coughs (B. R. Bocek 1984; D. E. Moerman 1986). V. K. Chestnut (1902) reported that the native people of Mendocino County, California, used a decoction of the roots for stomach pain, “female complaints,” and sore eyes. The species is the food plant for the bramble hairstreak butterfly (Callophrys viridis), Mormon metalmark (Apodemia mormo), western square-dotted blue (Euphilotes comstocki comstocki), and the federally endangered Smith’s dotted-blue (Euphilotes enoptes smithi). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 402. | FNA vol. 5, p. 314. |
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla |
Sibling taxa | ||
Synonyms | E. cernuum subsp. glaucescens, E. cernuum subsp. rotundifolium, E. rotundifolium var. angustius | |
Name authority | Bentham: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 14: 21. (1856) | Smith: in A. Rees, Cycl. 13(2): Eriogonum no. 3. (1809) |
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