Euphorbia
C. 35 species in Aust.; all states and territories
Erect annual or biennial herbs containing milky latex. Leaves alternate on lower stems, opposite or spirally arranged above; bases symmetric; stipules minute or absent. Flowers unisexual, grouped in a terminal inflorescence (cyathium) (Fig. 26) consisting of 1 naked female flower surrounded by 8–15 male flowers or the female flower absent, the whole surrounded by an involucre of 5 connate bracts. Cyathia usually arranged in cymes. Lobes of the involucre short, alternating with 4–5 spreading glands which often secrete nectar and are entire or horned. Male flowers each with 1 stamen; filament articulate; female flower with a stipitate 3-locular ovary. Ovary and fruit hanging out of the involucre over the space where the 5th gland is usually absent. Seed usually have a caruncle.