Aerial stem-parasitic shrubs, often robust, with epicortical runners bearing secondary haustoria. Leaves mostly opposite; venation pinnate. Inflorescencess axillary or rarely terminal, a raceme of decussate pairs of pedunculate dichasia (triads); bracts single under each flower. Fruit ellipsoid, usually with a persistent nipple-like style base.
Asia-Tropical:, New Guinea present; Philippines (Philippines present) from Java, Celebes and the Philippines south- eastwards to Australia and the Pacific as far as the Marquesas: present
25 species distributed from Java, Celebes and the Philippines south- eastwards to Australia and the Pacific as far as the Marquesas. In Malesia 21 species, with centres of species richness and diversity in the Philippines and New Guinea.
In Malesia some species are aggressive, with broad host ranges, sometimes occurring on cultivated trees.
In many Decaisnina species the inflorescence is presented horizontally and the triads are secund, all turning upwards on their peduncles so that the inflorescence has a brush-like appearance. In some species the short corolla tube formed by the coherent petals is dilated to form a distinct nectar chamber.
Circumscription of generic limits of Decaisnina and related genera has proved difficult, and has been revised progressively by Danser and then Barlow. Danser in his revisions included Decaisnina in Amylotheca, with some reservations, thus circumscribing the latter genus more broadly than here. For a conspectus of these and related genera see