Eriogonum parvifolium |
Eriogonum leptocladon |
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dune wild buckwheat, sea cliff buckwheat, seacliff wild buckwheat |
fine branch wild buckwheat, sand buckwheat, sand wild buckwheat |
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Habit | Shrubs, matted to spreading or rounded, 3–10 × 5–20(–25) dm, thinly tomentose or glabrous, greenish. | Shrubs, erect to spreading, not scapose, (2–)3–10(–12) × 5–15(–20) dm, white-tomentose to floccose, or green and nearly glabrous. | ||||||||
Stems | spreading, sometimes matted, often with persistent leaf bases, up to 1/2 or more height of plant; caudex stems absent or matted; aerial flowering stems prostrate, spreading, or erect, slender, solid, not fistulose, 0.2–1 dm, thinly tomentose or glabrous. |
spreading, often without persistent leaf bases, up to 1/2 height of plant; caudex stems absent or spreading in moving sand; aerial flowering stems spreading, slender, solid, not fistulose, 0.3–1 dm, white-tomentose, floccose to glabrate or glabrous. |
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Leaves | cauline, fasciculate, infrequently 1 per node; petiole 0.1–0.7 cm, floccose; blade lanceolate to round, 0.5–3 × 0.3–0.8(–1.2) cm, lanate to tomentose abaxially, mostly glabrous and olive green to green adaxially. |
cauline, 1 per node; petiole 0.2–0.5 cm, tomentose to floccose; blade linear-lanceolate to linear-oblanceolate to narrowly oblong, or lanceolate to narrowly elliptic, 1.5–4 × 0.2–0.8(–1.2) cm, densely white-tomentose abaxially, less so and greenish adaxially, margins plane, infrequently revolute. |
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Inflorescences | capitate to cymose, 20–30 × 2–10 cm; branches dichotomous, thinly tomentose or glabrous; bracts 3, scalelike, triangular, and 1–2 mm, or leaflike, usually elliptic, and 5–20 × 2–10 mm. |
cymose, open, 5–40 × 10–50 cm; branches dichtomous proximally, often with involucres racemosely arranged proximally, tomentose to floccose or glabrate, occasionally glabrous; bracts 3, scalelike, linear to triangular, 1–3(–6) mm. |
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Peduncles | absent. |
absent. |
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Involucres | 2–7 per cluster, turbinate-campanulate, (2.5–)3–4 × 2–3.5 mm, floccose to glabrate; teeth 5, erect, 0.5–0.9 mm. |
1 per node, turbinate to turbinate-campanulate, 1.5–3 × 1–2 mm, tomentose to floccose or glabrous; teeth 5, erect, 0.4–0.7 mm. |
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Flowers | 2.5–3 mm; perianth white to pinkish or greenish yellow, glabrous; tepals connate proximally, monomorphic, obovate; stamens exserted, 2.5–3.5 mm; filaments pilose proximally. |
(2–)2.5–3.5 mm; perianth white or pale yellow to yellow, glabrous; tepals connate proximal 1/4–1/3, essentially monomorphic, oblong to broadly obovate; stamens slightly exserted, 2–4 mm; filaments sparsely pilose proximally. |
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Achenes | brown, 2.5–3 mm, glabrous. |
light brown, 2.5–3.5 mm, glabrous except for minutely papillate beak. |
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2n | = 40. |
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Eriogonum parvifolium |
Eriogonum leptocladon |
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Phenology | Flowering year-round. | |||||||||
Habitat | Sandy beaches, dunes, and bluffs or sandy to gravelly inland slopes and flats, coastal grassland and chaparral communities, oak and pine woodlands | |||||||||
Elevation | 0-300 m (0-1000 ft) | |||||||||
Distribution |
CA
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AZ; CO; NM; UT
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Discussion | The native range of Eriogonum parvifolium is restricted to coastal and near-coastal areas (Los Angeles, Monterey, Orange, San Diego, San Luis Obispo, Santa Barbara, and Ventura counties). The coastal expression (var. parvifolium) has thickened leaf blades (0.5–1.5 × 0.3–0.8 cm) and simple or dichotomous inflorescences of compact clusters of involucres containing white to rose flowers. Highly compact and dense mat-forming plants on rocky bluffs immediately next to the ocean were named var. crassifolium; those with yellow flowers were named var. lucidum. The inland form with thin leaf blades (1.5–3 × 0.3–0.8 cm) and highly-branched, cymose, white-flowered inflorescences is perhaps worthy of continued recognition as var. paynei, although there is no sharp distinction between the extremes. Several expressions of the seacliff wild buckwheat are in cultivation, and unfortunately the California Department of Transportation is using the species in roadside plantings, with the result that it is now established in Santa Clara County. Every effort should be made to halt its introduction beyond its native range. The species is the food plant for two federally endangered butterflies, the El Segundo dotted-blue (Euphilotes battoides allyni), near Los Angeles, and Smith’s dotted-blue (Euphilotes enoptes smithi), near Monterey. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 3 (3 in the flora). Eriogonum leptocladon is localized on moving sands on the Colorado Plateau. It is not unusual, therefore, for portions of the shrub to be buried in sand, especially the main, woody trunk from which the flowering stems arise. In the Four Corners area three species share portions of overlapping ranges, and herbarium material from there can be difficult to separate. In northwestern New Mexico, var. ramosissimum approaches E. effusum, and in eastern San Juan County the two can be distinguished only by the open, spreading inflorescence branching pattern of var. ramosissimum as compared to the densely branched, compact inflorescence of E. effusum. In the field, the former is confined to sandy areas whereas the latter is typically on heavier, usually clayey soils. In south-central Utah, var. ramosissimum approaches E. nummulare. There, both are found on moving sands, and only the degree of stoutness of the branches can be used to differentiate them when cauline leaves are absent. For the most part, the inflorescence branches of E. nummulare are more rigid and stouter than those of var. ramosissimum, which tend to be flexible and slender. When leaves are present, those of the former are broader and more apically rounded compared to those of the latter. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 5, p. 300. | FNA vol. 5, p. 249. | ||||||||
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | E. parvifolium var. crassifolium, E. parvifolium subsp. lucidum, E. parvifolium var. lucidum, E. parvifolium subsp. paynei, E. parvifolium var. paynei | E. effusum subsp. leptocladon | ||||||||
Name authority | Smith: in A. Rees, Cycl. 13(2): Eriogonum no. 2. (1809) | Torrey & A. Gray: in War Department [U.S.], Pacif. Railr. Rep. 2(1): 129. (1857) | ||||||||
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