Synadenium

Shrubs or small trees, with branches fleshy, cylindrical, containing copious caustic milky latex; monoecious. Leaves alternate, usually large and fleshy; stipules modified as small but conspicuous dark brown glands. Inflorescence with sessile cyathia in dichotomously branching axillary cymes, usually crowded into pseudoumbels at branch apices; bracts at base of involucres paired, persistent. Involucres with an entire (rarely lobed), spreading, furrowed, glandular rim and 5 fringed lobes. Sepals and petals 0 or rudimentary. Male flowers reduced to individual stamens which are arranged in 5 groups opposite involucral lobes; stamens shortly exserted from involucre; bracteoles present. Female flowers: solitary within involucre, surrounded by male flowers, sessile or on short pedicel, pedicel elongating slightly in fruit; perianth reduced to 3-lobed rim below ovary; ovary 3-locular, with 1 pendulous ovule in each locule; styles 3, united below, with bifid stigma. Fruit a dehiscent capsule. Seeds with a sessile, often rudimentary caruncle. x = 9 (polyploidy).