Atriplex hortensis

Linnaeus

Sp. Pl. 2: 1053. 1753

Common names: Garden orach
Synonyms: Atriplex nitens Schkuhr
Treatment appears in FNA Volume 4. Treatment on page 332. Mentioned on page 322, 323.
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Illustrator: Bee F. Gunn
Herbs, green to yellowish or reddish, 5–15(–25) dm, glabrous. Stems erect, mostly branched. Leaves mostly opposite or mostly alternate; petiole 0.3–4+ cm; blade green on both sides, ovate or ovate-lanceolate to cordate-hastate at base, 15–180 × 8–135 mm, margin entire or more rarely irregularly toothed or lobed, apex attenuate to acuminate or rounded. Inflorescences of spikes disposed in leafless panicles. Staminate flowers 5-merous. Pistillate flowers dimorphic, some ebracteolate and with 5-parted perianth, others without perianth enclosed by a pair of sessile or very shortly stipitate bracteoles. Fruiting bracteoles samaralike, orbicular to oval or ovate, compressed, 5–18 mm, united only at base, entire, faces smooth. Seeds of ebracteate flowers black, horizontal, convex, 1–2 mm wide, lustrous; those of bracteolate flowers olivaceous brown, vertical, flat, 3–4.5 mm wide, dull. 2n = 18.

Phenology: Flowering summer–fall.
Habitat: Roadsides, canal and stream banks, lake shores, disturbed sites and gardens
Elevation: 0-2200 m

Distribution

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Alta., B.C., Man., Ont., Que., Sask., Yukon, Alaska, Calif., Colo., Conn., Idaho, Ill., Ind., Iowa, Mass., Minn., Mont., Nebr., Nev., N.J., N.Y., N.Dak., Oreg., S.Dak., Utah, Wash., Wis., Wyo., Asia.

Discussion

Atriplex hortensis has been widely grown as a potherb, has escaped from cultivation, and is now established especially in moist ruderal sites. It is easily distinguished by its rounded, samaralike, entire, and smooth fruiting bracteoles, and the presence of two kinds of pistillate flowers, the one enclosed by bracteoles and lacking sepals, the other without bracteoles but subtended by sepals.

Atriplex nitens (see list of excluded taxa) is distinguished from A. hortensis in Flora Europea (P. Aellen 1964b) by having leaf blades densely white scurfy beneath, the distal surface lustrous, as opposed to green and dull for A. hortensis. Occasional specimens, treated here as A. hortensis, have leaves somewhat scurfy.

References

None.

Lower Taxa

No lower taxa listed.