* Bark: Dark, fissured into broad, scaly. At first bronze green, later reddish brown, finally dark gray or brown. Very full of tannic acid.
* Wood: Dark brown, sapwood lighter; heavy, hard, strong, smooth, close-grained, durable in contact with the ground. Used for fencing, fuel, sleepers. Sp gr., 0.7499; weight of cu. ft., 46.73 lbs.
* Winter buds: Soft brown, ovate, acute, 6-13 mm long.
* Leaves: alternate, 9-20 cm long, three to four times the width, obovate to oblong-lanceolate, wedge or rounded at the base, toothed, rounded teeth acute, apex rounded or acute. Bud convolute, yellow green or bronze, shining above, very pubescent below. When full grown are thick, firm, dark yellow green, somewhat shining, and pale green and pubescent below, primary veins conspicuous. In autumn full pass to yellow to yellow-brown. Petioles stout or thin. Stipules linear to lanceolate, caducous.
* Flowers: May, when the leaves have grown by a third. Staminate flowers in hairy catkins 5-8 cm long, calyx pale yellow, hairy, deep lobes 7-9, 7-9 stamens, anthers bright yellow. Pistillate flowers in short spikes, green stems, strong, hairy, scaly involucre pubescent, stigmas short, bright red.
* Acorns: Annual, alone or in pairs; nut oval, rounded or acute at apex, glossy brown, 30-30 mm long, with glass, enclosing half to one third of the nut, thin, light brown, tuberculate near the base. Scales small. Pepita white, sweet.
Source : http://es.wikipedia.org/wiki/Quercus_prinus