Acanthaceae

Queensland

Either flowering or fruiting material is needed to operate this key. For genera where there is only one Queensland species, the full name is given. Cystoliths are calcium carbonate concretions that occur in many species of Acanthaceae. They occur mainly in the leaves, but may also be found on the stems, bracts and calyx-lobes. They are typically rod-shaped, but may also be circular, ellipsoidal or boomerang-shaped. Their shape and size is diagnostic for some species or genera. They are best observed on the upper leaf surface in dried material – if they are not seen immediately on the first leaf, search other leaves, especially close to the leaf margin.