This was neglected in Ky. until the 1980s, and it may be more widespread than records indicate. Although still treated as a variety by some authors (Cr, FNA 26), burdickii generally seems distinct from tricoccum (Jones 1979, Sitepu 2018; J, W; see also michiganflora.net). Intermediate plants have not been documented in Ky. However, plants from cooler Appalachian regions may form a segregate somewhat transitional to tricoccum (Sitepu 2018). Also, plants from the Great Lakes region and mid-west may be taxonomically distinct from plants in and around the Interior Low Plateans. The two species have similar northeastern ranges, but burdickii is locally predominant in midwestern regions and the Interior Low Plateaus, especially on drier base-rich soils (including most of the Bluegrass region). Both species seem to have significant disjunct occurrences in hilly regions of c. Ky. and c. Tenn. (Ch), but further checking of identifications is desirable across their ranges. A. burdickii differs from typical tricoccum mostly clearly in its leaves, which are usually narrower (ca. 2-4 cm versus 5-8 cm), without a distinct petiolar base, silvery bluish-green when fresh and the base white (versus bright green with a distinct reddish/pink petiole); also, its bulbs are usually narrower (up to 1-1.5 cm versus 2-3 cm). In both species, leaves senesce and disppear during Jun. But burdickii usually flowers with the leaves in early Jun (or late Jun further north); tricoccum flowers after the leaves in late Jun and Jul (or even Aug in cooler regions). Compared to typical tricoccum, burdickii has umbels with fewer flowers on average (mostly 10-20 versus 20-60), usually on more erect, shorter pedicels (ca. 10-15 mm versus 15-25 mm), with shorter spathe bracts (ca. 1-2 cm versus 2-3 cm); also, scapes are usually shorter (ca. 13-16 cm versus 25-35 cm). However, these differences in the inflorescence appear to be less clearcut in Ky. compared to further north and east (FNA 26, W); indeed most tricoccum in central Ky. may have relatively small umbels that are similar to those of burdickii.