This is a widespread eastern species of dry rocky or sandy soils in open woodland or grassland with some bare ground; but it is uncommon to absent on the southeastern Coastal Plain (K, W, FNA 25). Included here are relatively glabrous plants that have been named var. werneri (Scribn.) Mohlenbrock; HC also indicated that this taxon has relatively small spikelets (ca. 2.2-2.3 mm long versus 2.2-2.7 mm). Var. werneri is relatively frequent in more northern regions, but within Ky. it does not appear to have significant difference in distribution. In Missouri, Ladd & Thomas (2015) have revived this taxon as a species, together with a different set of diagnostic characters: and "more fidelity to high quality acidic woodland communities." Their characters for werneri are as follows: ligule of largest vernal leaves a short distinct line of hairs many times wider than long (versus 3-6 times wider than longest point) and usually backed by a glabrate adaxial leaf surface (versus glabrate); occasional vernal leaves with a distinct rounded M-shaped cross section (versus flattened); leaves often thicker, deeper green, and more strongly basally disposed. However, they stated: "aside from spikelet length, every other character of D. werneri is more similar to D. depauperatum than to D. linearifolium." It remains possible that werneri represents plants of hybrid origin (FNA 25). Deeper investigation of this problem is needed in Ky. Also, the closely related midwestern species, D. perlongum (Nash) Freckmann is expected in western regions, being known in s. Ill. and "throughout" Mo. (K, FNA 25; Ladd & Thomas 2015).