This differs from typical oligosanthes in several distinctive characters (Hitchcock & Chase 1950; W, FNA 25). However, initial analysis of DNA suggests that the two taxa may not be clearly separated (Majure et al. 2023). Spikelets of scribnerianum have less elongated shape (2.7-3.5 x 2-2.4 mm versus 3.4-4.2 x 1.7-2 mm), and are often glabrous (versus sparsely pubescent); blades tend to be broader (mostly 6-15 mm versus 4-9 mm), and ligules are shorter (1-1.5 mm versus 2-3 mm). D. scribnerianum has a widespread range centered in the midwest, and usually occurs on base-rich soils. It is reported to intergrade with oligosanthes locally, and it may also hybridize with malacophyllum, acuminatum and other species (FNA 25); see also notes under malacophyllum. Typical oligosanthes usually occurs on sandy soils from the Great Lakes to Coastal Plain, but reports from Ky. have not been fully verified (M). There may be colls. of typical oligosanthes from CALL and MCRA (EKY), as annotated by R. Naczi. Some Ky. colls. mapped here under scribnerianum have also been misidentified as D. wilcoxianum (Vasey) Freckmann (= oligosanthes var. w.), a taxon closer to linearifolium that occurs in the upper midwest but that remains unknown in Ky. (M).