From the Greek syn — together, adeno — gland, referring to the continuously fused glandular rim of the floral involucre.
Shrubs or small trees, evergreen or deciduous, perennial, male and female flowers on the same plant; stems and foliage with white latex. Indumentum of simple, multicellular hairs, generally absent. Stipules entire, conspicuous, modified into dark brown glands, persistent. Leaves alternate, stalkless to stalked, unlobed, penninerved, without glands; margins entire to toothed. Inflorescences axillary, pseudanthial and regular, comprising numerous bisexual involucres in dichotomously branching cymes, bracted; involucres with an entire glandular rim and 5 fringed lobes. Male flowers stalked; calyx lobes absent; petals absent; disk absent; stamens solitary. Female flowers stalked; calyx lobes absent; petals absent; disk absent; ovary 3-chambered, ovules 1 per chamber; styles 3, shortly fused at base, divided into 2. Fruits capsular, dehiscent, 3-lobed, surface smooth. Seeds ovoid, carunculate, non-arilloid.
19 species in E and S tropical Africa. One species is semi-naturalised in SE Qld. 2 species are cultivated.
Cuttings. Frost-sensitive.
Involucres with an entire glandular rim and 5 fringed lobes.
Carter (1988).
Source: (2002). Euphorbiaceae. In: . Horticultural Flora of South-eastern Australia. Volume 3. Flowering plants. Dicotyledons. Part 2. The identification of garden and cultivated plants. University of New South Wales Press.
