Atriplex obovata |
Atriplex canescens |
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broadscale, mound saltbush, New Mexico saltbush, silver saltbush |
four-wing saltbu sh, four-wing shad-scale, hoary saltbush, shadscale, wingscale |
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Habit | Subshrubs, dioecious, clump forming, mainly 2–8 dm and as wide, woody at base. | Shrubs, dioecious or rarely monoecious, mainly 8–20 dm, as wide or wider, not especially armed. | ||||||||||||
Stems | stiffly erect; branchlets terete. |
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Leaves | tardily deciduous, alternate or proximal-most subopposite, shortly petiolate; blade gray green, oblong-ovate to elliptic or orbiculate, 8–30(–35) × 6–20 mm, margin entire or rarely dentate, apex rounded to retuse or obtuse. |
persistent, alternate, sessile or nearly so, blade linear to oblanceolate, oblong, or obovate, mainly 10–40 × 3–8 mm, margin entire, apex retuse to obtuse. |
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Staminate flowers | yellow, in clusters 2–3 mm wide, borne in panicles 6–30 cm. |
yellow (rarely brown), in clusters 2–3 mm wide, borne in panicles 3–15 cm. |
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Pistillate flowers | in small, very numerous glomerules in axils of elongated, terminal leafy-bracteate spikes or finally paniculate. |
borne in panicles 5–40 cm. |
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Seeds | brown, 2.4–2.8 mm. |
1.5–2.5 mm wide. |
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Fruiting | bracteoles sessile or substipitate, 4–5 × 5–9 mm, base broadly cuneate, margin sharply toothed, apical tooth subtended by 2–6 equal or smaller teeth, faces smooth or rarely tuberculate. |
bracteoles 8–25 mm, as wide, on stipes 1–8 mm, with 4 prominent wings extending the bract length, united throughout, wings dentate to entire, apex toothed, surface of wings and body smooth or reticulate. |
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2n | = 18, 36+. |
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Atriplex obovata |
Atriplex canescens |
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Phenology | Flowering summer–fall. | |||||||||||||
Habitat | Fine-textured substrates, with salt desert shrub and lower pinyon-juniper communities | |||||||||||||
Elevation | 1500-2000 m (4900-6600 ft) | |||||||||||||
Distribution |
AZ; CO; NM; TX; UT; Mexico
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AZ; CA; CO; ID; KS; MT; ND; NE; NM; NV; OK; OR; SD; TX; UT; WA; WY; AB; Mexico
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Discussion | This species forms hybrids with Atriplex confertifolia and A. gardneri varieties (see var. bonnevillensis). Materials from the vicinity of the type locality of the species in South Dakota are low subherbaceous plants that differ from our shrubby tall material. However, the type area is presently covered with water from a dam on the Missouri River, and it is not possible to exclude the possibility of A. canescens as it has been interpreted for the past century to have existed at that site during the Lewis and Clark Expedition, if that is indeed where the lectotype was collected. Varieties 4 (4 in the flora). Nuttall’s new combination Atriplex canescens was based on Calligonum canescens Pursh. Watson based his new name A. nuttallii directly on A. canescens Nuttall, i.e., including the citation of Nuttall’s “Genera, 1. 197,” and on its basionym, C. canescens. The name A. nuttallii is thus a nomenclatural synonym of A. canescens and was thus illegitimate at its inception. It cannot be resurrected by even the most sophisticated arguments. A sheet of Atriplex canescens, noted as “a shrub,” taken by Nuttall on the 1810 Missouri River expedition is extant in the Lambert herbarium (PH). It bears several, obviously shrubby, staminate flowering branches, but the only pistillate branch is very immature. The name A. gardneri, also cited provisionally by Watson within the concept of A. nuttallii, clearly has priority over other names for that widely distributed species complex. Attempts at leptotypification of the name nuttallii by J. McNeill et al. (1983) and H. C. Stutz and S. C. Sanderson (1998) are both superfluous, the name being illegitimate. C. A. Hanson (1962) noted the similarity between the occasional wingless fruiting bracteoles of Atriplex canescens and A. gardneri var. falcata. He noted further that the bracts of both species lack lateral teeth subtending the terminal ones, have terminal teeth united half their length, and have indurate bracts. Whether such similarity indicates relationship or mere coincidence is open to question. However, A. canescens is known to form hybrids with most, if not all, portions of the gardneri complex and with other woody species whose range it overlaps as well. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 4, p. 371. | FNA vol. 4. | ||||||||||||
Parent taxa | Chenopodiaceae > Atriplex > subg. Pterochiton | Chenopodiaceae > Atriplex > subg. Pterochiton | ||||||||||||
Sibling taxa | ||||||||||||||
Subordinate taxa | ||||||||||||||
Synonyms | A. greggii, A. jonesii, A. obovata var. tuberata | Calligonum canescens, A. nuttallii | ||||||||||||
Name authority | Moquin-Tandon: Chenop. Monogr. Enum., 61. (1840) | (Pursh) Nuttall: Gen. N. Amer. Pl. 1: 197. (1818) | ||||||||||||
Web links |