A deciduous or almost evergreen shrub or small tree up to about 20 ft high; buds ovoid, slightly downy; young stems soon glabrous. Leaves leathery, oblong to oblong-elliptic, 13⁄4 to 23⁄8 in. long, 5⁄8 to 2 in. wide, obtuse at the apex, glabrous on both sides except for a few scattered hairs beneath, main lateral veins in mostly five to seven pairs, intercalary veins present, margins dentate, crenate, or sinuate, the teeth usually mucronate; petiole 1⁄4 to 1⁄2 in. long. Fruits more or less as in Q. faginea but scales of acorn-cups usually swollen.
Native of the N. Aegean and N.W. Anatolia, rare in cultivation. The galls produced by this oak are used in dyeing, whence the specific epithet, and also in medicine.
Q. boissieri Reut. ex Boiss. Q. infectoria subsp. boissieri (Boiss.) Gurke – Allied to Q. infectoria, but branchlets tomentose, at least when young; leaves larger, up to almost 5 in. long in some varieties, 11⁄4 to sometimes almost 3 in. wide, adult leaves rarely quite glabrous beneath and often persistently tomentose; lateral veins in seven to eleven pairs, fairly straight and parallel; intercalary veins rare except on leaves of the second flush; margins of leaves dentate, sometimes merely undulate, or occasionally quite entire; petiole up to almost 1 in. long.
Q. boissieri is of wider distribution than Q. infectoria, from Cyprus and Anatolia to western Iran and the Caucasus, south to Palestine, and is often a quite tall, forest-forming tree. It is subdivided into varieties with a lengthy synonymy, but the species is so rare in cultivation that a detailed treatment is beyond the scope of this work. There is an example at Kew obtained from James Booth of Hamburg, planted in 1870, which measures 58 × 61⁄4 ft (1967).
Some very striking variants of Q. boissieri occur in Cyprus, judging from the specimens in the Kew Herbarium.