12.
Atriplex rosea
Linnaeus, Sp. Pl., ed. 2. 2: 1493. 1763.
Tumbling orach
Herbs
, erect, coarse, 1-10(-20) dm.
Stems
simple or more commonly divaricately branching throughout, branches terete; herbage whitish scurfy to glabrate.
Leaves
alternate, short petiolate, blade prominently 3-veined, ovate to lanceolate, mainly 12-80 × 6-50 mm, margin irregularly sinuate-dentate and often subhastately lobed or rarely some entire, apex acute to obtuse.
Flowers
in axillary glomerules or interrupted terminal spikes.
Staminate flowers
with 4 or 5 sepals.
Pistillate flowers
in axillary glomerules of 5-10.
Fruiting bracteoles
prominently 3-5-veined, sessile or short stipitate, (3-)4-6(-10) mm and as wide, sometimes subhastately lobed at base, conspicuously dentate, sharply tuberculate to almost smooth on faces.
Seeds
dimorphic: brown, 2-2.5 mm wide, or black, 1-2 mm wide; radicle inferior.
2
n
= 18.
Flowering mid summer-fall. Disturbed sites, often in riparian habitats or in barnyards or on animal bed grounds, along roadsides and irrigation canals, with juniper, sagebrush, rabbitbrush, pinyon-juniper,
Salsola, Chrysothamnus, Atriplex
spp., and other weedy species; 0-2600 m; introduced; Alta., B.C., N.S., Ont., Sask.; Ariz., Calif., Colo., Fla., Idaho, Mass., Mich., Mo., Mont., Nebr., Nev., N.J., N.Mex., N.Y., N.Dak., Ohio, Oreg., Pa., Utah, Wash., Wis., Wyo.; Eurasia.
At least some early collections were from ballast dumps at harbors on both coasts. It seems probable that the plants were quickly spread inland from initial centers of introduction by birds and more recently along railroads.
