Description

Key Characters:

Growth Form: Annual or perennial herbs, occasionally (on islands) subshrubs.

Stems:

Roots:

Leaves: Leaves simple. Usually basal, sometimes cauline and alternate or opposite. Blades undifferentiated from petioles and apparently representing expanded petioles. Base often sheathing at base. Margins entire to subentire, toothed, or lobed. Petioles present or absent. Stipules absent.

Flowers: Flowers in bracteate spikes or heads, but bracteoles absent. Flowers usually wind–pollinated, bisexual (perfect) or rarely unisexual (and then plants monoecious or gynomonoecious), sometimes cleistogamous. Calyx 4-lobed, the lobes imbricate, the anterior pair sometimes partly to nearly completely connate. Corolla 4-lobed, scarious, the lobes imbricate. Stamens 4, alternate with the corolla lobes; filaments adnate to corolla tube; anthers long–exserted, dithecal, opening by longitudinal slits. Ovary superior, 2-carpellate, with as many cells, placentation axile; ovules 1–40 per cell, anatropous or hemitropous; style 1, terminal, slender; stigma usually 2-lobed.

Fruit: Fruit a membranous; circumscissile capsules; achene; or small nut; enclosed in the persistent calyx. Seeds with well-developed; firm; translucent endosperm.

Ploidy:

Habitat:

Elevation Range: