Leaves: alternate, simple, stipulate
Inflorescences: staminate catkin with 2-3 flowered cymules subtended by scale-like bractlets; pistillate catkin with 1-3 flowered cymules.
Flowers imperfect, regular.
Sepals: 2-4 (-6), distinct or absent
Stamens: 2-6 (8), distinct or filaments basally connate
Ovary: 2 carpels, connate, ovary inferior (2 locules) or superior (1 locule) with 1 axile ovule per locule, styles 2.
Fruit: achene, nut, samara