This variable species is widespread across eastern and central North America, with both diploid and tetraploid races (Peirson et al. 2012). Several colls. from Ky., especially eastern regions, appear transitional to the southeastern var. haleana Fern., with more robust, branched habit, and more reduced leaves on the branches. However, that variety intergrades broadly with typical northern plants (Cr), and it may not deserve recognition (FNA 20). The western var. longipetiolata (MacKenzie & Bush) Palmer & Steyermark has been recently treated as ssp. decemloba (DC.) Brammall ex Semple (FNA 20; see also, Ladd & Thomas 2015). This is a more distinct tetraploid, with larger floret dimensions and more elongated, less crenate leaves; 2n = 36 (versus 18 in typical nemoralis). It has been reported from Ky. by Harvill (1941), F and others (M), but no convincing colls. are known (check colls. of C.W. Short at PH).