Below are pictures of the three principal varieties used for making cognac.

Leaf and grapes of the Ugni Blanc.

In the spring they have yellow leaves and in summer they are big and unevenly coloured. The leaves consist of three or five lobes. The sinuses, were the leaf is attached to the stem, is slightly opened and often has lobes that overlap and have teeth of mediocre length. On the underside of the leaf there is a somewhat thicker layer with apressed hairs.
Long bunches of round grapes, turning to pink when growing older. The grapes are relatively small and contain a lot of juices.

Leaf and grapes of the Folle Blanche.

They are sensible to night frost because they blossom early in the season. They are highyielding plants. Full grown it has five lobes and deep lateral sinuses. The central sinus is closed or just slightly opened. With short teeth in pointed arch forms.
The grapes are medium sized.

Leaf and grapes of the Colombard.

The leaf has three big lobes with small teeth and an open sinus. There is a thin layer with upright hairs on the underside of the leaf.
The grape is mediocre sized, somewhat cylindrical shaped, with plenty of juice.
It is very sensitive for frost in the spring, because the shoots bud early.