Atriplex pentandra |
Atriplex subg. Obione |
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seas hore orach |
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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. | Plants annual or perennial, monoecious to subdioecious or less commonly dioecious. |
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. |
usually with or, uncommonly, without Kranz anatomy. |
Staminate flowers | in short, dense, naked terminal spikes or panicles; calyx 5-cleft, lobes green keeled. |
with calyx lobes crested or not. |
Pistillate flowers | fascicled in axils. |
lacking or rarely with a perianth (in A. covillei, A. pleiantha, and A. suckleyi), enclosed by a pair of bracteoles. |
Seeds | brown, 1–1.5 mm. |
erect; radicle typically superior (except in A. pleiantha), erect, tip adjacent to styles. |
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. |
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Bracteoles | cuneate to ovate or obovate united at least to middle, faces with tubercles or crests or smooth. |
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Atriplex pentandra |
Atriplex subg. Obione |
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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) |
Mainly w North America; also Old World |
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.) |
Species ca. 33 (27 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 4, p. 362. | FNA vol. 4. |
Parent taxa | ||
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Axyris pentandra, A. texana, A. wardii | subg. Obione, A. section Obione |
Name authority | (Jacquin) Standley: in N. L. Britton et al., N. Amer. Fl. 21: 54. (1916) | (Gaertner) S. L. Welsh: Rhodora 102: 418. (2001) |
Web links |