Atriplex pentandra |
Atriplex canescens |
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seas hore orach |
four-wing saltbu sh, four-wing shad-scale, hoary saltbush, shadscale, wingscale |
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Habit | Herbs, annual or perennial, sprawling to erect, often suffrutescent at the base, much branched and clump-forming, 3–10 dm. | Shrubs, dioecious or rarely monoecious, mainly 8–20 dm, as wide or wider, not especially armed. | ||||||||||||
Stems | obtusely angled, finely scurfy when young. |
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Leaves | sessile or short petiolate; blade paler abaxially, oblong or rhombic-ovate to broadly obovate or narrowly oblong or narrowly elliptic, 10–30 × (1–)3–15 mm, thin, base rounded to cuneate, margin repand-dentate or sinuate-dentate to undulate or distal ones or all of them entire, apex rounded to acute, mucronate, densely white scurfy abaxially, grayish green and usually glabrate adaxially. |
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 | in short, dense, naked terminal spikes or panicles; calyx 5-cleft, lobes green keeled. |
yellow (rarely brown), in clusters 2–3 mm wide, borne in panicles 3–15 cm. |
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Pistillate flowers | fascicled in axils. |
borne in panicles 5–40 cm. |
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Seeds | brown, 1–1.5 mm. |
1.5–2.5 mm wide. |
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Fruiting | bracteoles sessile or with stipes to 0.5 mm, broadly cuneate-orbiculate, compressed, (2–) 2.5–4.5 × (1.5–)2.6–5 mm, usually as broad as or broader than long, much thickened at maturity, united only at truncate or broadly cuneate base, margin deeply and acutely dentate, faces with 2, sometimes swollen, dentate crests or covered with irregular, conic-acute, corky tubercles, seldom smooth. |
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 pentandra |
Atriplex canescens |
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Phenology | Flowering summer–fall. | |||||||||||||
Habitat | Sandy seashores, coastal salt marshes | |||||||||||||
Elevation | 0-50 m (0-200 ft) | |||||||||||||
Distribution |
AL; CT; FL; GA; LA; MA; MS; NC; SC; TX; West Indies; South America (Venezuela and Colombia to Peru) |
AZ; CA; CO; ID; KS; MT; ND; NE; NM; NV; OK; OR; SD; TX; UT; WA; WY; AB; Mexico
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Discussion | D. S. Correll and M. C. Johnston (1970), treated both Atriplex texana and A. wardii at the specific level. The diagnostic features used to distinguish them, dentate versus entire leaf blades and smooth versus tuberculate faces of fruiting bracteoles, fail singly and in combination. Both taxa were regarded by H. M. Hall and F. E. Clements (1923) as variants of typical A. pentandra, and this worker tentatively agrees with those authors’ conclusions. Specimens from Galveston, Texas—the type locality of A. wardii—are apparently intermediate with A. mucronata (see below) and form the basis on which A. wardii was founded. Some of those specimens have been annotated by me and others as A. mucronata. The plants have entire leaves more closely matching those of A. mucronata, but the small fruiting bracteoles, though usually lacking tubercles on the faces, are of similar proportions to those of typical A. pentandra. Atriplex pentandra and A. mucronata are certainly very closely allied. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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. 362. | FNA vol. 4. | ||||||||||||
Parent taxa | ||||||||||||||
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Synonyms | Axyris pentandra, A. texana, A. wardii | Calligonum canescens, A. nuttallii | ||||||||||||
Name authority | (Jacquin) Standley: in N. L. Britton et al., N. Amer. Fl. 21: 54. (1916) | (Pursh) Nuttall: Gen. N. Amer. Pl. 1: 197. (1818) | ||||||||||||
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