Phyllode

Phyllodes are modified petioles or leaf stems, which are leaf-like in appearance and function.

[1] In some plants, these become flattened and widened, while the leaf itself becomes reduced or vanishes altogether.

Some important examples are Euphorbia royleana which are cylindrical and Opuntia which are flattened.

Sometimes, especially on younger plants, partially formed phyllodes bearing reduced leaves can be seen.

The genus, Daviesia, in the family Fabaceae, is characterised in part by the plants having phyllodes.