A taxonomic survey of the genus Vitis L. (Vitaceae) in Italy, part II: the ‘Euro-American’ hybrids

Abstract

New names are assigned to two ‘Euro-American’ nothospecies of Vitis originating from the artificial crossing of Euro-Mediterranean V. vinifera with two American species, employed both as rootstocks and for wine production, and spontaneously occurring in Italy and other European countries: V. ×bacoi (= V. riparia × V. vinifera) and V. ×goliath (= V. riparia × V. rupestris × V. vinifera). Original and detailed descriptions, illustrations and information on distribution and ecology are provided, along with an updated identification key. Late-season leaf pigmentation, presence/absence of phylloxera galls, ripe berries flavor, and seed morphology proved to be useful characters for the identification of the treated species and nothospecies. Nomenclatural aspects regarding V. riparia × V. vinifera are also discussed.