Eriogonum inflatum |
Eriogonum thurberi |
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bottle stopper, desert trumpet, Indian pipeweed |
Thurber eriogonum, Thurber's buckwheat, Thurber's wild buckwheat |
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Habit | Herbs, erect, perennial, occasionally flowering first year, 1–10(–15) dm, glabrous, usually glaucous, grayish. | Herbs, spreading, annual, 0.5–4 dm, glabrate, glabrous or sparsely glandular, greenish, grayish, or reddish. |
Stems | caudex compact; aerial flowering stems erect, solid or hollow and fistulose, (0.2–)2–5 dm, glabrous, usually glaucous, occasionally hirsute proximally. |
caudex absent; aerial flowering stems erect, solid, not fistulose, 0.3–1 dm, often sparsely tomentose and glandular proximally. |
Leaves | basal; petiole 2–6 cm, hirsute; blade oblong-ovate to oblong or rounded to reniform, (0.5–)1–2.5(–3) × (0.5–)1–2(–2.5) cm, short-hirsute and grayish or greenish on both surfaces, sometimes less so or glabrous and green adaxially, margins occasionally undulate. |
basal; petiole 1–3 cm; blade oblong to narrowly ovate, 0.8–4.5 × 0.5–3 cm, densely white-tomentose abaxially, floccose or glabrous and greenish adaxially, margins often crenulate. |
Inflorescences | cymose, open, spreading to erect, 5–70 × 5–50 cm; branches occasionally fistulose, glabrous, usually glaucous; bracts 3, scalelike, 1–2.5(–5) × 1–2.5 mm. |
cymose, mostly diffuse, 5–30 × 5–50 cm; branches sparsely glandular to glabrate or glabrous; bracts 3, scalelike, 1–2.5 × 1–2.5 mm. |
Peduncles | erect, straight, filiform to capillary, 0.5–2(–3.5) cm, glabrous. |
erect, straight, capillary, 0.5–2.5 cm, glabrous and glandular-puberulent distally. |
Involucres | turbinate, 1–1.5 × 1–1.8 mm, glabrous; teeth 5, erect, 0.4–0.6 mm. |
broadly turbinate, 1.8–2 × 1.8–2 mm, minutely glandular-puberulent; teeth 5, erect, 0.4–0.6 mm. |
Flowers | (1–)2–3(–4) mm; perianth yellow with greenish or reddish midribs, densely hirsute with coarse curved hairs; tepals monomorphic, narrowly ovoid to ovate; stamens exserted, 1.3–2.5 mm; filaments glabrous or sparsely pubescent proximally. |
1–1.7 mm; perianth white with greenish or reddish midribs, becoming red, glandular-puberulent with a tuft of long white hairs adaxially; tepals dimorphic, those of outer whorl broadly pandurate or flabellate, those of inner whorl oblanceolate; stamens included, 0.7–1.2 mm; filaments mostly glabrous. |
Achenes | light brown to brown, lenticular to 3-gonous, 2–2.5 mm, glabrous. |
brown to black, usually lenticular, 0.6–0.8 mm, glabrous. |
2n | = 32. |
= 40. |
Eriogonum inflatum |
Eriogonum thurberi |
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Phenology | Flowering year-round. | Flowering year-round. |
Habitat | Sandy to gravelly washes, flats, and slopes, mixed grassland, saltbush, creosote bush, mesquite, and sagebrush communities, pinyon and/or juniper woodlands | Sandy flats, washes, and slopes, saltbush, greasewood, and creosote bush communities, oak, pinyon and/or juniper woodlands, (montane conifer woodlands in Mexico) |
Elevation | -30-1800(-2000) m (-100-5900(-6600) ft) | 100-1200 m (300-3900 ft) |
Distribution |
AZ; CA; CO; NM; NV; UT; Mexico (Baja California, Sonora)
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AZ; CA; NM; Mexico (Baja California, Sonora)
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Discussion | The cause of the fistulose stem and inflorescence branches in Eriogonum inflatum was imaginatively attributed by A. M. Stone and C. T. Mason (1979) to the larvae of gall insects. This fallacy continues to appear in the literature. Greenhouse studies have shown that stems of this and some other species of the genus inflate without the presence of any insects. Other researchers have shown that the inflation involves a build-up of CO2 within the stems, which take over as the primary photosynthetic body as leaves wilt or eventually dry up and fall away from the plant (C. D. Osmond et al. 1987). Not all individuals of E. inflatum will have fistulose stems and branches, as this feature is partly a function of available moisture: the drier the conditions, the less pronounced the inflation. Stems produced in the summer tend to be inflated less frequently than those produced in the spring. The “annual” phase of Eriogonum inflatum is distinct from its truly annual relatives. Its flowering stems and inflorescence branches are distinctly grayish, whereas those of the true annuals are green or yellowish green. As circumscribed here, Eriogonum inflatum occurs in Arizona, southern and east-central California, western Colorado, northwestern New Mexico, central and southern Nevada, and southern and eastern Utah. Some Native Americans occasionally ate newly emerged stems of Eriogonum inflatum (S. A. Weber and P. D. Seaman 1985; M. L. Zigmond 1981). The hollow stems were used as drinking tubes (Weber and Seaman) and pipes (E. W. Gifford 1936). This wild buckwheat is a food plant for the desert metalmark butterfly (Apodemia mormo deserti). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Eriogonum thurberi is common to abundant but rarely weedy in northwestern Mexico, southern California (Inyo, Los Angeles, Orange, Riverside, San Bernardino, and San Diego counties), and southern Arizona (Cochise, Gila, Graham, Maricopa, Mohave, Pima, Pinal, Santa Cruz, and Yavapai counties). It just enters New Mexico (Grant County). It and E. thomasii are the annual members of the E. cernuum complex typically found on the Mojave and Sonoran deserts, with E. thurberi extending farther to the east and E. thomasii farther to the north. The two occasionally grow together. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 386. | FNA vol. 5, p. 403. |
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma |
Sibling taxa | ||
Synonyms | E. glaucum, E. inflatum var. deflatum, E. trichopes subsp. glaucum | E. cernuum subsp. thurberi, E. cernuum subsp. viscosum |
Name authority | Torrey & Frémont: in J. C. Frémont, Rep. Exped. Rocky Mts., 317. (1845) | Torrey: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 176. (1859) |
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