Description

Key Characters:

Growth Form: Trees or shrubs deciduous, monoecious.

Stems:

Roots:

Leaves: Leaves simple. Alternate. Margins usually doubly serrate, rarely simply serrate, lobulate, or entire. Veins pinnate. Petiolate. Stipules present, free, often deciduous, rarely persistent.

Flowers: Flowers in male inflorescence precocious, elongate, pendulous, with numerous overlapping bracts; each bract usually subtending a small dichasium with 1–3 male flowers; stamens as many as and opposite sepals or, if sepals obsolete, then stamens of inflorescence to 20; filaments very short, connate or nearly so; anthers 2-loculed, thecae connate or separate, opening by longitudinal slits. female inflorescence pendulous or erect, with numerous overlapping bracts; each bract subtending a small dichasium with 2 or 3 flowers; calyx with 1–6 scalelike lobes, or obsolete; petals absent; ovary inferior, 2-loculed; styles 2, free; ovules 2, or 1 by abortion, pendulous from near apex of each locule. Flowers unisexual. Sepals sometimes present in staminate flowers or absent. Corolla (petals) absent. Stamens (1–)4–6; anthers 2-locular, dehiscing by longitudinal slits, pollen sacs often ± distinct. Ovary inferior or superior; ovules 1-2 per locule, pendulous; styles 2, distinct or nearly so; stigmas dry.

Fruit: Nut or nutlet; winged or not. Seeds 1 per fruit; with straight embryo and flat or thickened cotyledons; without endosperm.

Ploidy:

Habitat:

Elevation Range: