Eriogonum effusum |
Eriogonum fasciculatum |
|||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
spreading buckwheat, spreading wild buckwheat |
California buckwheat, California wild buckwheat, eastern Mojave buckwheat, eastern Mojave wild buckwheat |
|||||||||||||
Habit | Shrubs, spreading, not scapose, (1.5–)2–5(–7) × 5–15 dm, grayish- to reddish-brown-tomentose to floccose and gray or, rarely, thinly floccose and greenish. | Shrubs or subshrubs, compact to spreading or rounded and more or less erect, occasionally decumbent, infrequently scapose, (1–)2–15 × 2–25(–30) dm, tomentose to canescent, floccose, or glabrous. | ||||||||||||
Stems | spreading to erect, typically without persistent leaf bases, up to 1/2 height of plant; caudex stems absent; aerial flowering stems erect to spreading, slender, solid, not fistulose, 0.3–0.8 dm, floccose or glabrous. |
sprawling or spreading to erect, often with persistent leaf bases, up to 1/2 or more height of plant; caudex stems absent or matted to spreading; aerial flowering stems erect to spreading, slender, solid, not fistulose, 0.3–2.5(–3) dm, tomentose, canescent, or glabrous. |
||||||||||||
Leaves | cauline, 1 per node; petiole 0.2–0.7 cm, tomentose to floccose; blade oblanceolate to oblong or obovate, (1–)1.5–3 × (0.2–)0.3–0.7 cm, densely white-tomentose abaxially, white-floccose to glabrate or green and glabrous adaxially, margins plane. |
cauline, 1 per node or fasciculate; petiole 0.1–0.3 cm, canescent; blade linear to linear-oblanceolate or oblanceolate, 0.6–1.5(–1.8) × 0.05–0.4(–0.6) cm, white-tomentose or canescent to subglabrous abaxially, tomentose or canescent and grayish, subglabrous, or glabrous and green adaxially, margins often revolute. |
||||||||||||
Inflorescences | cymose, 10–30(–40) × 10–40 cm; branches dichotomous, white-floccose to glabrate or subglabrous; bracts 3, scalelike, triangular, 0.5–2(–5) mm. |
cymose, infrequently cymose-umbellate or capitate, compact to open, occasionally flat-topped, 0.2–20 × 0.2–15 cm; branches dichotomous, infrequently absent, tomentose to canescent or glabrous; bracts usually 3, scalelike, triangular, and 1–3 mm, or leaflike, linear to oblanceolate, and 3–10 × 1–3 mm. |
||||||||||||
Peduncles | absent or mostly erect, slender, 0.3–2.5 cm, floccose. |
absent. |
||||||||||||
Involucres | 1 per node, turbinate, 1.5–2.5(–3) × 1–2 mm, tomentose to floccose; teeth 5, erect, 0.3–0.6 mm. |
(1–)3–8 per cluster, turbinate to campanulate, 2–4 × 1.5–3 mm, canescent, pubescent, glabrous, or subglabrous; teeth 5, erect, 0.3–1.2 mm. |
||||||||||||
Flowers | 2–4 mm; perianth yellow, glabrous; tepals connate proximal 1/4, essentially monomorphic, elliptic to obovate; stamens mostly exserted, 2–4.5 mm; filaments sparsely pilose proximally. |
2.5–3 mm; perianth white to pinkish, glabrous or pubescent; tepals connate proximal 1/4, monomorphic, usually elliptic to obovate; stamens exserted, 2.5–5 mm; filaments subglabrous or pubescent proximally. |
||||||||||||
Achenes | brown, 2–2.5 mm, glabrous. |
light brown to brown, 1.8–2.5 mm, glabrous. |
||||||||||||
Eriogonum effusum |
Eriogonum fasciculatum |
|||||||||||||
Phenology | Flowering Jun–Sep. | |||||||||||||
Habitat | Sandy to rocky slopes and flats, mixed grassland and sagebrush communities, juniper and montane conifer woodlands | |||||||||||||
Elevation | 1200-2500 m (3900-8200 ft) | |||||||||||||
Distribution |
CO; MT; NE; NM; SD; WY
|
AZ; CA; NV; UT; including nw Mexico
|
||||||||||||
Discussion | Eriogonum effusum is rather common on the northern Great Plains and along the eastern slope of the Rocky Mountains in central and eastern Colorado, southeastern Montana, western Nebraska, northern New Mexico, southwestern South Dakota, and southeastern Wyoming. Some specimens from Chaffee County, Colorado, are thinly floccose and greenish (Atwood & Welsh 29689, BRY) and thus similar to E. leptocladon. A collection from Pyramid Lake, Washoe County, Nevada (Frandsen & Brown 182, NESH) is clearly mislabeled. A roadside collection of E. effusum gathered near Little America, Sweetwater County, Wyoming, in 1961 (G. Mason 4025, ASU) was an introduction that has not persisted. The spreading wild buckwheat is occasionally merged with Eriogonum microthecum even though the two are morphologically distinct and their ranges do not overlap. Plants in New Mexico are sometimes difficult to distinguish from the related E. leptocladon var. ramosissimum. The species is the food plant for the Rita dotted-blue butterfly (Euphilotes rita). A hybrid between Eriogonum effusum and E. pauciflorum has been named E. ×nebraskense Rydberg [E. multiceps Nees subsp. nebraskense (Rydberg) S. Stokes; E. pauciflorum Pursh var. nebraskense (Rydberg) Reveal]. The hybrid is known from Weld County, Colorado; Cheyenne and Kimball counties, Nebraska; and Converse and Platte counties, Wyoming. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 5 (4 in the flora). Eriogonum fasciculatum is a complex, polyploid series of variants that are generally distinct but often difficult to distinguish morphologically. Variety emphereium Reveal is confined to central Baja California, Mexico. The introduction of Eriogonum fasciculatum as a decorative roadside plant by the California Department of Transportation is resulting in hybrid populations involving E. cinereum. The aggressively weedy and (for Arizona) exotic variety foliosum is rapidly invading the native habitat of var. polifolium. Members of E. fasciculatum are food plants for several butterflies, notably the Bernardino dotted-blue (Euphilotes bernardino), lupine blue (Plebeius lupini), Mormon metalmark (Apodemia mormo), and Behr’s metalmark (A. virgulti). Probably the butterfly most commonly seen with the species is the nut-brown hairstreak (Satyrium saepium), which frequents plants in full flower. Eriogonum fasciculatum is also the most important native source of honey in California. This widespread species was used extensively by Native Americans for a variety of ailments. Its application for pain and headaches (D. P. Barrows 1900; K. Hedges 1986; E. W. Voegelin 1938) was rather common, as was its general use for diarrhea (Hedges; Voegelin). M. L. Zigmond (1981) reported that the Kawaiisu lined their acorn granaries with leaves of var. proliferum to keep out rain—a daunting challenge given the size of the leaves! L. Hinton (1975) reported the use of a decoction of dried flowers and roots to maintain a healthy heart, and M. C. Stevenson (1915) indicated that a powder derived from the roots was used by the Zuñi to treat wounds, whereas a root decoction was taken for colds and hoarseness. B. R. Bocek (1984) reported that the Costanoan Indians of California used a decoction of the plant to treat unspecified urinary problems. F. H. Elmore (1943) reported the use of a decoction of var. proliferum by the Navajo (Diné) people as an anti-witchcraft medicine. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||||||||||
Key |
|
|||||||||||||
Source | FNA vol. 5, p. 248. | FNA vol. 5, p. 297. | ||||||||||||
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla | ||||||||||||
Sibling taxa | ||||||||||||||
Subordinate taxa | ||||||||||||||
Synonyms | E. microthecum var. effusum | |||||||||||||
Name authority | Nuttall: Proc. Acad. Nat. Sci. Philadelphia 4: 15. (1848) | Bentham: Trans. Linn. Soc. London 17: 411. (1836) | ||||||||||||
Web links |