This is a globally rare species of thin dry calcareous woods, grassland transitions and roadsides in southeastern states (K), virtually all east of the Mississippi Rv., except in se. Mo. where it has disappeared (Y). Most sites are in or near the Black Belt (Ala., Miss.), western Highland Rim (Tenn., Ky.), Ridge-and-Valley (Ala., Ga., Tenn.), and Piedmont (N.Car., Va., Md., N.J.). It is considered endangered or locally extinct in all states except Ala., where there are at least 10-20 sites (NS). Until recently, the only Ky. record was an unverified report from RAB, with no coll. located. In 2016, B. Yahn discovered several plants in thin red cedar woods and glades at one locality in Mammoth Cave National Park (EDMO). There are also verified records from adjacent Montgomery Co. in Tenn. (Ch). D. ochroleucum can be distinctive in the field, with creamy flowers and creeping habit, but non-flowering plants are easily confusable with rotundifolium (W, Y). Its leaflets have L/W of ca. 1.2-1.9 (versus 0.9-1.2), the terminal one with generally acute apex (versus rounded); lower leaflet surfaces have mostly short uncinate hairs (versus long straight spreading hairs), and the veins are conspicuously raised (versus generally inconspicuous); flowers are white to yellowish (versus blue-purple or rarely white); loments are uncinate-puberulent only along the sutures (versus whole surface), and often twisted (versus flat). At the Ky. site, plants are somewhat ascending when in flower, but rotundifolium tends to remain relatively low. Both species share stipules that are ovate, persistent, slightly to strongly clasping at the base, 6-12 mm long (W).