This variable hexaploid (2n = 48) consists of largely cultivated plums that are derived from the Eurasian species, P. cerasifera Ehrh. (2n = 16, 24), or P. spinosa L. (2n = 32, 48) or hybrids between these two species. In contrast, the modern "Japanese-style" plums of global markets are self-fertilizing diploids (2n = 16) derived mostly from cerasifera (which includes the common purple-leaved cultivar) and East Asian species, especially P. salicina Lindl. (including the popular cultivar "Methley" in se. USA). There are several interbreeding subspecies or varieties of original Eurasian domestica. Fruits may be purple with a waxy bloom (including Bullace or Damson), or green (including Greengage) or small and yellow (including Mirabelle). Also, especially in southeastern states, there appear to be contributions in some cultivars from native American plums (Boonprakob et al. 2001). Although varied cultivars of domestica are widely grown and often persistent in eastern states, there is little evidence that they have spread from seed. Ky. records include colls. from persistent trees in LYON and TRIG (Chester 1992; APSC). Old English cultivars may be referred to P. domestica ssp. instititia (L.) C.K. Schneider, with yellow-green to blue-purple fruits (including later-ripening spherical "bullaces" and earlier oval "damsons"). But one of the most reliable fruit-producers in Kentucky is the Mirabelle Plum, P. domestica subsp. syriaca (Borkh.) Janch. ex Mansf., which originates from Turkey and Syria. It has relatively small leaves and yellowish to red early-ripening (Jun-Jul) fruits, similar in size to the native plums. These Eurasian plums (Prunus section Prunus) are distinguished from American plums (section Prunocerasus) by the smaller number of flowers per cluster (mostly 1-2 versus 4-5), their stones are more sculptured, and fruits are often bluish-black (versus just reddish-purple). Leaves tend to be broader in shape and flat or nearly so (versus usually somewhat folded).