Euphorbiaceae

Non-woody (herbaceous) terrestrial plants that are mostly annual, have pollen-producing and seed-producing structures on separate flowers, either on the same plant or separate plants, mostly don’t have petals and usually have a three-lobed ovary with styles that may branch one or more times.

Arrangement of flowers solitary to clustered (in patterns resembling cymes, racemes or panicles), sometimes with a large bract at the base. Flowers usually symmetrical in all directions (radially), often inconspicuous, located at the ends of the stems or branches, or where the leaves join the stem (axils). Flowers often highly modified, in Euphorbia plants (see following paragraph). Sepals usually 2 to 6, most commonly 5, separate to slighly fused, sometimes absent. Petals usually none, but plants may have bracts or other structures that resemble petals. Stamens 1 to numerous, their stalks separate to fused, inconspicuous to very showy. Carpels usually 3, fused; ovary located above the point of attachment of other flower parts, usually 3 lobed. Styles usually 3, sometimes very showy. Nectar disk usually present. Fruit a dry capsule that splits into segments, that in turn split open to release seeds. Seeds may have a fleshy brightly-coloured coating.

Euphorbia flowers resembling individual flowers in spurges are actually highly-modified clusters of flowers. Each cluster (cyanthium) has a cup-shaped base formed by partial fusion of several bracts. In the centre is a single stalked small seed-producing flower that consists of a single pistil with 3 styles, surrounded by several pollen-producing flowers, each consisting of a single stamen on jointed stalks. The tips of each bract that helps form the cup-shaped base remains as a lobe. There are usually nectar glands, each attached at the indentation between each lobe. In some species, white or coloured appendages resembling petals, project from the edges of the glands.

Leaves usually alternate and spiral or 2-ranked, sometimes opposite, simple to lobed or compound, entire to toothed. Stipules usually present.

Stem and leaves with simple hairs or none. Stems upright to sprawling over the ground.

Spurges produce a strong unpleasant milky or coloured latex that is poisonous, and may cause a reaction similar to poison ivy in some people if it contacts the skin.

Family members mostly tropical, sparingly represented in temperate regions.