Kentucky Plant Atlas




  
«previous» Taxon rank is 1543 «next»
Ebenaceae Diospyros pubescens (virginiana var. pu., ?var. platycarpa)
Diospyros pubescens Pursh
ALI: no HAB: 9,6,7,8?, n/a, D?, 4 ABU: g9?, s7?, -2
Treatment and mapping here is provisional. After initial notes by F.A. Michaux (1805, 1819), Pursh (1814: vol. 1, p. 265) initially described this species from "lower counties of Virginia, Carolinas and Georgia". Nuttall (1846: vol. 1, p. 46) recognized it as a variety "from Louisiana collected by Mr. Teinturier, and a very similar, but less pubescent variety, was found in Georgia by the late Dr. Baldwyn". As a variety, the taxon has been recognized in the wild mostly along the lower Mississippi and further west, especially in Ark., Mo. and Tenn. (Cr, W; SERNEC), where it is most distinct in wetlands (as also reported by D. Estes, pers. comm.). It is probably associated with the higher chromosome number (2n = 90 versus 60) that has been shown within some eastern Diospyros (Baldwin & Culp 1941, Raymond 2006, Pomper et al. 2020). However, variation often appears to be more complex or continuous, perhaps involving past hybridization with D. texana Scheele (2n = 30) to the southwest; moreover, it is importnt to check the native versus cultivated status of samples, and more analysis is needed (Y, FNA 8). The leaves of pubescens are thinly but persistently covered with relatively long hairs below (versus glabrous or glabrescent), subcordate (versus cuneate to rounded) and often relatively large (up to ca. 24 x 12 cm versus ca. 10 x 6 cm); also, twigs are hirsutulous (versus glabrous). Fruits tend to be relatively large but may vary much in size; Rafinesque (1828) included pubescens with his var. microcarpa. Var. platycarpa Sarg. is another potential segregate of virginiana, with unusually large fruit but perhaps more variable pubescence. That variety has been included by some authors under pubescens, as "an early ripening extreme with depressed fruits up to 7.5 cm across" (F) that is known mostly from Okl., Ark., Mo., Kans. and probably cultivated further east. In w. and s. Ky., relatively large fruits (ca. 3-5 cm across) are sometimes encountered in the wild, but never as large as reported for var. platycarpa. The cultivar "Yates" originates from s. Ind., with fruits 3-6 cm across and unusually large leaves (ca. 10-20 cm long) that are glabrous except for persistent hairs along major veins; its fruits ripen and drop mostly in November but remain relatively astringent until frozen for days or weeks. Cultivars of eastern Diospyros with larger fruit mostly have 2n = 90, and tend to produce parthenocarpic (seedless) fruit when pollinated by wild trees with 2n = 60 in Ky. and Tenn., (Pomper et al. 2020). Despite circumstantial evidence, there has been virtually no published research on parthenogenesis in North American Diospyros since the first reports by Woodburn (1911) and Mottier (1912), which were from Indiana. However, parthenogenesis in the Japanese D. kaki Thunb. has been researched in detail (e.g. Chijiwa et al. 2013); that species has reported 2n = 90 (including seed-bearing cultivars), 107-114 and 135 (mostly seedless cultvars)