Trees , winter-deciduous. Terminal buds present, long, tapered in maturity, all scales imbricate. Leaves: stipules prominent on new growth, soon deciduous. Leaf blade thin, secondary veins unbranched, ± parallel, extending to margin, each vein ending in acute or obscure tooth. Inflorescences unisexual, axillary in new growth leaves; staminate inflorescence lax, loosely capitate cluster of flowers; pistillate inflorescence short, stiff, cupule 1, terminal. Staminate flowers: sepals connate; stamens 6-16; pistillode typically absent. Pistillate flowers 2 per cupule; sepals distinct; carpels and styles 3. Fruits: maturation in 1st year following pollination; cupule 4-valved, valves distinct, ±completely enclosing nuts until maturity, prickly, prickles stout, unbranched, short, not obscuring surface of cupule, internal valves absent; nuts 2 per cupule, sharply 3-angled, slightly winged. x = 12.

Staminate fls in small heads on drooping peduncles, the bracts caducous, the stamens 8-16; pistillate fls usually paired on a short peduncle, concealed by the numerous subulate bracts; ovary 3-locular; fr a sharply 3-angled nut; 1-seeded, borne normally in pairs within the accrescent, 4-valved involucre; trees with straight-veined lvs, a vein running to each tooth; fls appearing with the lvs, the staminate from the lower axils, the pistillate from the upper. 10, N. Temp.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

©The New York Botanical Garden. All rights reserved. Used by permission.