Commemorating Lady Diana Beaumont (d. 1831) of England.
Lianas, evergreen; latex white. Stems woody, without spines. Leaves opposite, stalked; blade well developed; colleters absent at base. Inflorescence terminal or axillary, cymose. Flowers scented, stalked. Corolla bellshaped; tube cylindrical; lobes convolute, overlapping to the right in bud. Corolline corona comprising 5 pouches in front of the petal sinuses. Stamens conspicuously protruding on long twisted filaments, attached near top of tube, forming cone around style head. Disk cup-shaped or shallowly 5-lobed. Fruit syncarpous, a capsule, dehiscent into 2 halves; seeds 1-many, tapering to each end, not winged, hairy at one end.
One species commonly cultivated. Frost-sensitive.
Scandent liana, corolla bell-shaped, anthers converging around style head and protruding on long filaments.
9 species in Asia and Malesia.
Source: (2002). Apocynaceae. In: . Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.