In its broad sense, P. aquilinum L. has a widespread (cosmopolitan) range over the globe, in temperate and subtropical regions. Based on recent revision (W and citations), P. latiusculum is a reasonable segregate that occurs mostly in eastern North America and East Asia, but it still contains five subspecies or varieties. Young shoots and roots of this genus have a long history of culinary uses in East Asia and elsewhere, but there is little or no record of this from eastern North America. Plants contain thiaminase (FNA 2) and carcinogens, especially the norsesquiterpene glucoside "ptaquiloside" (Smith & Seawright 1995); but correct cooking is reputed to remove these toxins.