Onagraceae

Deciduous non-woody (herbaceous) plants with bundles of needle-like crystals; flower parts in twos or fours, flowers symmetric in all directions (radially), the lowermost or outermost opening first and the main stem and its side branches often growing longer as the flowers develop (indeterminate inflorescence); floral tube (hypanthium) usually extending beyond the ovary (except in Primrose-willows) and deciduous, and ovary below the point of attachment of the other flower parts (inferior); Enchanter’s Nightshades, Evening-primroses, Fireweed and Primrose-willows.

Flowers in racemes or solitary, occur where the leaf joins the stem (axil). Sepals 2 to 4, often distinct, but sometimes initially fused, splitting and bending backwards when flowers are blooming. Petals separate, 2 to 4 (none in Primrose-willow), yellow, white, pink or purple. Sepals and petals deciduous. Stamens 2, 4 or 8, often alternately unequal, pollen-grains tending to form large clumps. Carpels 2 to 4, fused, style head- or disk-like, or 4-lobed. Fruit a chambered capsule that opens (dehiscent), or a small nut-like or bur-like structure that does not (indehiscent). Seeds sometimes with hooked bristles or a tuft of hairs.

Leaves simple, entire to toothed or lobed, alternate, opposite or whorled. Stipules absent or falling off very early.

Stems mostly upright, rarely creeping or partially floating.