Other images:
Voucher: Kostadinov 039, 040, (URV)
Brief description: Subgenus Erythrobalanus, red and black oaks. A large monoecious tree to 30 m with dark, thick bark with narrow furrows and pubescent twigs of the season. Leaves are simple, alternate, rounded at base, pinnately veined, deeply pinnately 1-4 lobed, with the lobes elongate, the terminal one sickle-shaped. The foliage and petiole are persistently tomentose; the margins are bristle-tipped. The leaves are highly variable, the juvenile one characteristically less deeply lobed. Flowers are unisexual, the staminate in slender catkins, the pistillate solitary or in small spikes. Fruits are a nut (acorn), partly enclosed by the persistent involucre -- the acorn cup. The acorn cup is deeply saucer-shaped. The acorns mature at the end of the second season and sprout at the beginning of the third.
Campus data: Frequent everywhere in the wild, not cultivated.