51�Թ�

Common petiole, cleft at the base, lacking glandule.

Common petiole swollen at the base, 2 stipules and 1 glandule.

Common petiole with two thorns united at its base and a small glandule on the upper part.

Petioles very short, with a pointed glandule on the inner surface of the base.

Principal petiole with one glandule at the base and often another higher up.