Atriplex tenuissima A. Nelson, Bot. Gaz. 34: 359. 1902; A. greenei A. Nelson; A. tenuissima var. greenei (A. Nelson) Fosberg; Obione tenuissima (A. Nelson) Ulbrich

Stems erect, intricately branched, 0.5-3 dm. Leaves: proximalmost blade linear, 4-20 × 2-3 mm, distalmost blade bracteate, sometimes ovate or ovate-lanceolate, densely grayish scurfy. Staminate flowers confined to a few distal axils. Fruiting bracteoles ovate or ovate-lanceolate in profile, (1.8-)2.3-2.7 × 1.5-2.1 mm, distal lobe typically larger and broader than lateral lobes, terminal tooth typically much largest or with this apparently displaced laterally.

Flowering summer-fall. Plants of saline bottoms, often in margins of marshy areas with salt grass, greasewood, and seepweed; 1500-2300 m; Colo., Utah, Wyo.

Specimens cited by H. M. Hall and F. E. Clements (1923) from central Utah within their concept of Atriplex wolfii in a strict sense have fruiting bracteoles in which the terminal, or apparently terminal, cusp is off-set from the median position, thus appearing to be lateral and lacking a terminal cusp. Other materials cited by them away from the south-central Colorado type locality of var. tenuissima bear bracteoles with a similar displacement of the terminal cusp. Hall and Clements placed such specimens within A. wolfii. Bracts of that type are unmatched among the materials of var. wolfii in southern Colorado. As interpreted here, the plants belong to var. tenuissima.