A small deciduous tree with dark brown or purplish-brown glabrous young stems. Leaves mostly obovate or oblong-obovate, usually rounded or obtuse at the apex and obliquely cordate at the base, 3 to 5 in. long, 11⁄2 to 21⁄2 in. wide, dark green, glabrous and somewhat lustrous above, underside paler with a few hairs along the midrib, margins with five to nine pairs of short fairly equal lobes; veins in seven to ten pairs, more or less parallel, running out to the apices of the lobes; intercalary veins absent or almost so; petiole yellowish, 3⁄4 to 1 in. long. Fruiting peduncles 11⁄4 to 31⁄4 in. long, bearing two to five fruits; cup similar to that of Q. robur but thicker; acorn ovoid, about 1 in. long, 1⁄2 in. wide.
Native of the western Transcaucasus, Turkey (including the European part), and E. Bulgaria. The main interest of this species is that, according to Mme Camus, it bears a marked resemblance to the fossil species Q. roburoides, which was widespread in Europe at the end of the Tertiary period and may have been the ancestor of the present-day Q. robur, Q. petraea, and allied species. Dr Schwarz places it in section Robur, as the only species of the series Primitivae. The primitive feature of this oak is the venation of the leaves: in Q. robur, which Q. hartwissiana resembles in its pedunculate fruits, the leaves have intercalary veins, i.e., veins running out to sinuses or fading away before they reach the margin of the leaf. In Q. hartwissiana all the laterals run out to the apices of the lobes and are more or less parallel – an unusual feature among European oaks, though it is shown by Q. petraea and its allies, which, in this respect, are nearer to the putative ancestral species.