Eriogonum strictum |
Eriogonum inflatum |
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Blue Mountain buckwheat, strict buckwheat |
bottle stopper, desert trumpet, Indian pipeweed |
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Habit | Herbs, erect, loosely to densely matted, not scapose, 1–5 × 1–10 dm, tomentose or glabrous. | Herbs, erect, perennial, occasionally flowering first year, 1–10(–15) dm, glabrous, usually glaucous, grayish. | ||||||||||||
Stems | spreading to erect, with or without persistent leaf bases, up to 1/4 height of plant; caudex stems absent or spreading to matted; aerial flowering stems erect to spreading, slender, solid, not fistulose, 1–3 dm, tomentose or glabrous. |
caudex compact; aerial flowering stems erect, solid or hollow and fistulose, (0.2–)2–5 dm, glabrous, usually glaucous, occasionally hirsute proximally. |
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Leaves | basal, 1 per node; petiole rarely twisted or curled, 1–6 cm, mostly tomentose; blade elliptic to ovate, 0.5–2.5(–4) × (0.3–)0.5–1.5 cm, lanate, tomentose to floccose on both surfaces, sometimes sparsely tomentose to floccose and greenish or floccose to subglabrous or glabrous adaxially, margins plane. |
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. |
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Inflorescences | umbellate-cymose to cymose, 1–20 × 3–25 cm; branches dichotomous, tomentose to floccose or less often glabrous; bracts 3, scalelike, triangular, 1–3 mm. |
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. |
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Peduncles | absent. |
erect, straight, filiform to capillary, 0.5–2(–3.5) cm, glabrous. |
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Involucres | 1 per node, rarely 2–5 per cluster, narrowly turbinate to turbinate-campanulate, 4–6 × 1.5–5 mm, tomentose or glabrous; teeth 5, erect, 0.5–1.3 mm. |
turbinate, 1–1.5 × 1–1.8 mm, glabrous; teeth 5, erect, 0.4–0.6 mm. |
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Flowers | 3–5(–6) mm; perianth yellow or white to rose or purple, glabrous; tepals connate proximally, dimorphic, those of outer whorl elliptic to nearly orbiculate, 2–3 × 2–3 mm, those of inner whorl oblanceolate to oblong, 3–4 × 1–2 mm; stamens included to slightly exserted, 2–5 mm; filaments pilose proximally. |
(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. |
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Achenes | light brown to brown, 3–3.5 mm, glabrous. |
light brown to brown, lenticular to 3-gonous, 2–2.5 mm, glabrous. |
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2n | = 32. |
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Eriogonum strictum |
Eriogonum inflatum |
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Phenology | 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 | |||||||||||||
Elevation | -30-1800(-2000) m (-100-5900(-6600) ft) | |||||||||||||
Distribution |
CA; ID; MT; NV; OR; WA
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AZ; CA; CO; NM; NV; UT; Mexico (Baja California, Sonora)
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Discussion | Varieties 4 (4 in the flora). Eriogonum strictum, E. niveum, and E. ovalifolium form a complex of closely related species differing in leaf, inflorescence branching, and flower features. Variety proliferum appears to be the basal entity of the complex, approaching both E. niveum and E. ovalifolium var. pansum in its pubescence and branching pattern. Also, specimens of var. proliferum are sometimes difficult to differentiate from E. nudum var. oblongifolium. Careful observation, though, will permit well-made collections to be easily distributed among the individual species. An alternative taxonomy is to reduce all of the taxa to E. ovalifolium and recognize a series of subspecies and varieties. It is possible that additional study will show that E. strictum is sufficiently distinct from its tomentose to floccose counterparts to justify recognition of E. proliferum. In that case, both var. anserinum and var. greenei would be assigned to the latter species. Or, one could follow C. L. Hitchcock et al. (1955–1969, vol. 2) and recognize subsp. strictum as distinct from subsp. proliferum, with the latter consisting of varieties proliferum, anserinum, and greenei. Members of the Eriogonum strictum are food plants for the Bauer’s dotted-blue butterfly (Euphilotes baueri). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
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Key |
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Source | FNA vol. 5, p. 317. | FNA vol. 5, p. 386. | ||||||||||||
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma | ||||||||||||
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Subordinate taxa | ||||||||||||||
Synonyms | E. glaucum, E. inflatum var. deflatum, E. trichopes subsp. glaucum | |||||||||||||
Name authority | Bentham: Trans. Linn. Soc. London 17: 414. (1836) | Torrey & Frémont: in J. C. Frémont, Rep. Exped. Rocky Mts., 317. (1845) | ||||||||||||
Web links |