Eriogonum corymbosum |
Eriogonum exaltatum |
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corymbed wild buckwheat, crispleaf buckwheat, crispleaf wild buckwheat, white wild buckwheat |
ladder buckwheat, ladder wild buckwheat |
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Habit | Shrubs or subshrubs, spreading, rounded, occasionally erect, rarely somewhat matted, not scapose, (0.5–)1.5–8(–15) × (2–)3–15(–23) dm, grayish- to reddish-brown-tomentose to floccose or glabrous, grayish or greenish. | Herbs, erect, annual, (0.5–)3–6(–10) dm, glabrous, glaucous, grayish. | ||||||||||||||||||||||||||||
Stems | spreading or erect, often with persistent leaf bases, up to 3/4 or more height of plant; caudex stems absent or somewhat matted; aerial flowering stems erect or nearly so, slender or occasionally stout, solid, not fistulose, (0.1–)1–2 dm, tomentose to floccose, occasionally glabrous. |
caudex absent; aerial flowering stems erect, solid, not fistulose, (0.5–)1–2 dm, glabrous. |
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Leaves | cauline, 1 per node; petiole 0.1–1.5 cm, tomentose to floccose; blade lanceolate to oblanceolate or elliptic to nearly orbiculate, rarely cordate, (0.5–)1–3(–4.5) × (0.3–)0.5–3(–3.5) cm, densely white-, tannish- or brownish-tomentose on both surfaces or less so to nearly glabrous and green adaxially, margins occasionally crenulate. |
basal; petiole 1–10 cm, tomentose; blade sub-cordate to orbiculate, (1.5–)2–5(–8) × (1.5–)2–5(–8) cm, densely white-tomentose abaxially, floccose to subglabrous and green adaxially, margins often wavy. |
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Inflorescences | cymose, rarely capitate or umbellate, diffuse to rather open, (1–)3–20 × 2–25(–30) cm; branches dichotomous, tomentose, floccose, or rarely glabrous; bracts 3, scalelike, usually triangular, and 1–3(–6) mm, or leaflike, 10–25 mm, and similar to leaf blades. |
cymose, spreading when immature, quickly becoming narrowly erect and strict with whiplike branches, (5–)10–50(–80) × 10–50 cm; branches glabrous, glaucous; bracts 3, scalelike, 1–1.5(–2) × 0.4–1 mm. |
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Peduncles | absent. |
absent or erect, straight, slender, 0.1–0.2 cm, glabrous. |
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Involucres | 1 per node, turbinate, (1–)1.5–3.5 × 1–2(–2.5) mm; teeth 5, erect, 0.3–1 mm. |
turbinate, 2–2.5(–3) × 1.5–2.5 mm, glabrous; teeth 5, erect, 0.5–1.5 mm. |
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Flowers | (1.5–)2–3.5 mm; perianth white to cream, pink, or pale yellow to yellow, glabrous or rarely sparsely pilose; tepals connate proximal 1/4–1/3, essentially monomorphic, oblanceolate to spatulate; stamens included to slightly exserted, 1–4(–5) mm; filaments typically pilose proximally. |
1.5–2 mm; perianth white with green or reddish midribs, becoming pinkish, glabrous; tepals dimorphic, those of outer whorl oblong, those of inner whorl lanceolate; stamens exserted, 1.5–2.5 mm; filaments pilose proximally. |
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Achenes | brown, 2–2.5(–3) mm, glabrous except for occasional papillate beak. |
dark brown to blackish, 3-gonous, 2–2.5 mm, glabrous. |
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2n | = 40. |
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Eriogonum corymbosum |
Eriogonum exaltatum |
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Phenology | Flowering May–Oct. | |||||||||||||||||||||||||||||
Habitat | Sandy to gravelly flats and slopes, saltbush, creosote bush, greasewood, blackbrush, and mesquite communities, rarely in pinyon-juniper woodlands | |||||||||||||||||||||||||||||
Elevation | 500-1400 m (1600-4600 ft) | |||||||||||||||||||||||||||||
Distribution |
AZ; CO; NM; NV; TX; UT; WY
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AZ; CA; NV; UT |
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Discussion | Varieties 8 (8 in the flora). Eriogonum corymbosum is a difficult complex of overlapping expressions, some of which are maintained here as taxonomically significant. Although perianth color is used to group the varieties, this feature is not consistent even in single populations. Therefore, population trends in perianth color must be noted in the field. Most of the varieties are then distinguished on the basis of leaf characters, and again, considerable variation can be seen in some populations. Still, the combination of flower color, leaf features, and geographic distribution should prove useful in distinguishing the varieties. S. L. Welsh et al. (2003) alluded to hybrid combinations involving Eriogonum corymbosum and other species. Aside from the instances involving E. brevicaule, discussed below, none has been confirmed. Most of the putative hybrids are misidentified specimens of E. lonchophyllum or collections of var. corymbosum in which the leaf-margins are not decidedly crisped, a feature usually seen only in fully mature plants. Eriogonum corymbosum was widely used by Native Americans. P. A. Vestal (1940) reported that the Hopi pressed boiled stalks into cakes that, when dried, were eaten with salt. J. W. Fewkes (1896) indicated that boiled leaves were mixed with cornmeal and water, and then baked into a kind of bread. S. A. Weber and P. D. Seaman (1985) indicated that A. F. Whiting was aware of a decoction of leaves (probably from var. glutinosum) being used for headaches. Variety glutinosum also was used primarily to treat tuberculosis, or at least as a cough medicine (D. E. Moerman 1986). Some of the expressions of Eriogonum corymbosum are attracting the interest of gardeners, a few are coming into cultivation, and several selections are now being developed. The plants are slow growing but can be transplanted with some degree of success. Members of the varieties are food plants for Ellis’s dotted-blue butterfly (Euphilotes ellisi). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Eriogonum insigne has been a troublesome taxon. The type, collected by E. Palmer in 1876, is a curious specimen from near Paragonah in Iron County, Utah. That expression has not been recollected and, after another frustrating review of the type material, it is now referred to E. deflexum, along with other odd specimens from southern Nevada and California that have always been difficult to assign. As a result, the tall, upright plants with long, whiplike branches of northwestern Arizona (Mohave County), southern Nevada (northeastern Clark and southern Lincoln counties), and southwestern Utah (southwestern Washington County), are now recognized under the name E. exaltatum. Some specimens remain problematic. Immature plants of E. exaltatum (Goodding 2302, GH, MIN, MO, NY, RM, UC) resemble E. bifurcatum. Specimens from Eureka Valley (DeDecker 4741, NY) and western Pahrump Valley (Abrams 14248, DS, GH, NY) in Inyo County, California, appear to belong to E. exaltatum. Like Eriogonum exaltatum, some populations of E. deflexum var. deflexum have nearly erect involucres. The plants from the Buried Hills (Nye and Clark counties, Nevada) are particularly odd. Single plants from a few collections in Kane County, Utah, have sessile, seemingly erect involucres in the forks of inflorescence branches. None of these plants has the characteristic long, whiplike branches of E. exaltatum, and they are not included in E. deflexum var. deflexum. The type of E. deflexum var. rectum from San Bernardino County, California (Reveal & Broome 6385, CAS, NY, US, etc.), has individual specimens with both deflexed and somewhat erect involucres, along with whiplike branches. Collections from Imperial and San Diego counties, previously associated with what is here termed E. exaltatum, are now considered specimens of E. deflexum. Clearly, more work is required to understand these species fully. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 5, p. 255. | FNA vol. 5, p. 397. | ||||||||||||||||||||||||||||
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma | ||||||||||||||||||||||||||||
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Synonyms | E. effusum subsp. corymbosum | |||||||||||||||||||||||||||||
Name authority | Bentham: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 14: 17. (1856) | M. E. Jones: Contr. W. Bot. 15: 61. (1929) | ||||||||||||||||||||||||||||
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