Atriplex pentandra |
Atriplex prostrata |
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seas hore orach |
fat-hen, hastate orache, hastate-leaf orache, spearscale orache, thin-leaf orache, thinleaf orach, triangle orache |
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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. | Herbs, monoecious, erect, decumbent or procumbent, branching, 1–10 dm; stems subangular to angular, green or striped. |
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. |
opposite or subopposite at least proximally; petiole (0–)1–3(–4) cm; blade triangular-hastate, lobes spreading, 20–100 mm and almost as wide, base truncate or subcordate, margin entire, serrate, dentate, or irregularly toothed, apex acute to obtuse. |
Flowers | in spiciform naked spikes 2–9 cm, sometimes forming terminal panicles; glomerules tight, contiguous or irregularly spaced. |
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Staminate flowers | in short, dense, naked terminal spikes or panicles; calyx 5-cleft, lobes green keeled. |
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Pistillate flowers | fascicled in axils. |
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Seeds | brown, 1–1.5 mm. |
dimorphic: brown, flattened, disc-shaped, 1–2.5 mm wide, or black, 1–1.5 mm wide; radicle subbasal, obliquely antrorse to spreading. |
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 green, becoming brown to black at maturity, triangular-hastate to triangular-ovate, veined or veins obscure, 3–5 mm, thin to thickened, spongy, base truncate to obtuse, margin united at base, lateral angles mostly entire, apex acute, faces smooth or with 2 tubercles. |
2n | = 18. |
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Atriplex pentandra |
Atriplex prostrata |
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Phenology | Flowering summer–fall. | Flowering in summer–fall. |
Habitat | Sandy seashores, coastal salt marshes | Sea beaches, salt marshes or other saline habitats |
Elevation | 0-50 m (0-200 ft) | 0-2000 m (0-6600 ft) |
Distribution |
AL; CT; FL; GA; LA; MA; MS; NC; SC; TX; West Indies; South America (Venezuela and Colombia to Peru) |
AZ; CA; CO; CT; DE; IA; ID; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; MT; NC; NE; NH; NJ; NM; NV; NY; OH; OR; PA; RI; UT; VA; WA; AB; MB; NB; NS; ON; PE; QC; SK; Eurasia [Introduced in North America]
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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.) |
Atriplex prostrata often grows with willow, tamarix, Scirpus (Schoenoplectus and Bulboschoenus segregates), Juncus, Distichlis, and Typha. Perhaps the phase along coastal eastern North America is indigenous, but this and the related Atriplex heterosperma evidently moved quickly from one palustrine habitat to another following subsequent introductions from the Old World. They were probably initially introduced as ballast waifs, and subsequently dispersed by waterfowl. The two species are now commonplace in lands within and adjacent to marshes in much of North America west of the initial sites of introduction. The name for the species taken up here follows the nomenclatural interpretation of J. McNeill et al. (1983). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 4, p. 362. | FNA vol. 4, p. 336. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Axyris pentandra, A. texana, A. wardii | A. triangularis |
Name authority | (Jacquin) Standley: in N. L. Britton et al., N. Amer. Fl. 21: 54. (1916) | Boucher ex de Candolle: in J. Lamarck and A. P. de Candolle, Fl. Franç. ed. 3, 3: 387. (1805) |
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