Justicia petiolaris is a relatively fast-growing perennial herb, 1m in height. Although each stem only bears a few flowers at a time, the total number is large and it gives a very attractive overall impression. The calyx has five green pointed lobes. The corolla is two-lipped. Flowers are mostly pink-purple, but may also be more blue-mauve in colour and they are followed by small capsules bearing seeds. The leaves are soft, oval-shaped, hairy and differ greatly in size on the same shrub.
It does very well in filtered shade and can be pruned after flowering.