Philenoptera violacea is a medium- to large-sized, deciduous to semi-deciduous tree up to 15 m tall with a wide-spreading, dense and rounded crown. The main stem is tall, straight and bare, occasionally bent and twisted. The bark is grey and flaking on older branches and stem, but smooth, light grey and covered with dense hairs on younger branches, exuding a sticky red sap when cut.

Leaves are large (70-200 mm long), unevenly compound with 1-3 pairs of opposite leaflets and one terminal leaflet, hard and rough in texture, shiny or glossy above and grey-green beneath, with prominent midribs. The terminal leaflets are always much bigger than the lower leaflets (about 180 mm long and 90 mm broad). Flowers are scattered, usually borne in dense terminal sprays 120-300 mm long at the tips of the branches, varying in colour from white and pink to bluish-pink, mauve or deep violet, and are sweet-scented. They appear from September to December, before or together with the new leaves. Fruit is a flat pod, non-splitting, relatively large (about 120 x 25 mm), hairless, tapering at both ends, persisting on the tree during winter, usually 2- or 3-seeded. 

The seeds are kidney-shaped, reddish, and compressed.