This taxon occurs mostly west of the highest Appalachian mountains, especially on calcareous sites in midwestern regions. Recognition as a species distinct from typical trioliatum may be reasonable, but more research is needed. Nomenclature has been confused (Rafinesque 1836, 4:29-31; Gm, F, K, W, Y). In Ky. aureum is clearly more common than trifoliatum, but some records need to be checked. W has separated it based on "golden-yellow" florwers (versus "dark maroon"); also, stems and leaves are rarely purplish (versus usually so). However, F and others have differentiated this taxon based on several characters: larger fruits (ca. 4-5 mm long versus 3-4 mm); yellow flowers (versus dark purple); larger umbels (usually 3-9 cm wide versus 1.5-3 cm); cauline leaves ternate to quinate (versus simple to ternate) with larger central leaflets (3-8 cm long versus 2-4.5 cm); simple basal leaves larger (3-10 cm long versus 1.5-5 cm); stems taller (3-15 dm versus 2-6 dm) and rarely purplish (versus often); rhizomes thicker (5-15 mm versus 3-5 mm). These plants are often confused with Zizia aptera.