This may be at least as widespread in Ky. as sinensis (Cr), but colls. should be checked in some cases. There is evidence of extensive hybridization between these two species in southeastern states, where most plants may be referable to X formosa Rehder (Trusty et al. 2008; W). In all species of Wisteria, a curious vegetative character is the retrorse-pointing hooks or wart-like growths on stems at leaf scars (Graves 1956), suggesting some function in climbing, or perhaps a thorny repellant to herbivores? All parts of plants, especially seeds, contain unusual triterpenoids, including the highly toxic glycoside known as "wistarin", but the complex chemistry remains poorly understood (e.g. Mohamed et al. 2012). One seed is enough to cause serious symptoms in a child (e.g. Kim et al. 2017).