Flower:

Panicle 1 to 8 inches long, usually oval to pyramidal in outline, the branches mostly spreading with the lower branches spreading to ascending, and branchlets appressed to the branch; occasionally the lowest branches are reflexed, and all branches may become erect and appressed to the stem in fruit. Spikelets (flower clusters) are overlapping on the tip half to 2/3 of a branch, green to purplish at flowering time, flattened, oblong to lance-elliptic, 3 to 7 mm (to ~1/3 inch) long with 2 to 7 florets; the uppermost floret may be sterile.

At the base of a spikelet is a pair of bracts (glumes) that are both blunt to pointed at the tip, awnless, hairless, light green to purplish with transparent whitish edging, obscurely veined, the lower glume .5 to 1.5 mm long, the upper glume 1.5 to 2.8 mm long. Surrounding a floret is a pair of bracts (lemma and palea), the lemma 2 to 3.5 mm long, longer than the upper glume, green to purplish, obscurely veined, the tip transparent whitish and blunt to pointed; the palea is about as long as the lemma. The thickened base of the floret (callus) is sparsely covered in short hairs.

Leaves and stems:

Leaves are mostly basal with with 2 to 4 alternate leaves mostly on the lower half of the stem. Leaves are up to 4 inches long, 1 to 4 mm wide, hairless, rough-textured, flat though may become rolled along the edges (involute) with age. The sheath is hairless. The ligule (membrane where the leaf blade joins the sheath) is 1 to 3 mm long, somewhat triangular, usually pointed at the tip, and lacks a fringe of hairs. Nodes are smooth.

Stems are hairless, unbranched, usually erect, occasionally prostrate from the base and rising from the lower node (genticulare), and multiple from the base forming clumps.

Fruit:

Spikelets dry to light brown at maturity. Individual florets drop away when mature, leaving the glumes behind persisting on the stalk. The grain (seed) is elliptic, brown, up to about 1.5 mm long.

Notes:

Nuttall's Alkaligrass is a native grass of wet, saline grasslands, found in Minnesota's western counties where it reaches the eastern edge of its natural range; it is mostly considered adventive east of Minnesota. It is somewhat variable, but generally distinguished by hairless leaves and sheaths; ligule 1 to 3 mm long, more or less triangular and pointed at the tip; panicle branches spreading to erect, branchlets appressed to the branch, the lowest branches only occasionally reflexed, and all branches may be erect in fruit; spikelets without awns, green to purplish at flowering time with 2 to 7 florets; glumes unequal, lemmas 2 to 3.5 mm long, the tips thin, whitish, blunt to pointed at the tip.

Most similar is the related, non-native Weeping Alkaligrass (Puccinellia distans), which tends to be a smaller plant more often with decubment stems, has panicle branches spreading with the lowest branches usually reflexed, ligules usually less than 2 mm long and straight across to somewhat convex at the tip, and lemmas usually less than 2 mm long that are ragged and straight across to broadly rounded at the tip.