Atriplex powellii

S. Watson

Proc. Amer. Acad. Arts 9: 114. 1874.

Common names: Powell’s orach
Endemic
Synonyms: Obione powellii (S. Watson) Ulbrich
Treatment appears in FNA Volume 4. Treatment on page 352. Mentioned on page 327, 328.

Herbs, dioecious or sometimes sparingly monoecious. Stems slender to stout, mainly 1–5(–7) dm, branching almost throughout; herbage pubescent with scurfy and arachnoid hairs. Leaves alternate, proximalmost on petioles (3–)5–30 mm, becoming subsessile or short petiolate distally; blade 3-veined, ovate to rhombic or orbiculate to elliptic, 0.4–5 × 0.2–3 cm, base rounded to cuneate, margin entire, apex acute to obtuse. Staminate flowers with calyx 4–5-lobed. Fruiting bracteoles sessile, ovate to oblong or broadly cuneate or pan-duriform, 1.5–5.5 × 1.5–5 mm, thick, united to apex, apex truncate to cuspidate or tridentate, surfaces with thickened processes or rarely smooth. Seeds greenish, yellowish, or brown, 0.9–2 mm; radicle superior. 2n = 18.

Distribution

V4 677-distribution-map.gif

Alta., Sask., Ariz., Colo., Idaho, Mont., N.Mex., Nebr., Oreg., S.Dak., Utah, Wyo.

Discussion

Varieties 2 (2 in the flora).

Selected References

None.

Key

1 Leaves mostly conspicuously 3-veined, proximalmost with petioles 0.5-2.5(-3.5) cm, distalmost bracteate leaves typically short petiolate; fruiting bracteoles easily discerned at bract bases; plants mostly dioecious; from Alberta and Saskatchewan s to Utah and New Mexico Atriplex powellii var. powellii
1 Leaves inconspicuously, if at all, 3-veined, proximalmost with petioles 0.5-1.5(-2) cm, distalmost bracteate leaves typically sessile; fruiting bracteoles apparent only by removing the subtending bract; plants evidently monoecious; local distribution in se Utah. Atriplex powellii var. minuticarpa