Piper, in Family Piperaceae, is a large genus of shrubs, trees or vines.
Stems are often swollen at the nodes.
The alternately arranged leaves are simple and on a petiole.
The petiole often has sheathing below.
Leaves often have an unequal base and venation can be pinnate or palmate.

Inflorescences are spikes in the leaf axils or opposite the leaves.
Spikes can be upright, drooping or curved.
Tiny flowers have no stalk but have one bract.
Flowers, with no perianth, are male or female.

Male flowers usually have 4 stamens (1 to 6).
Female flowers have an ovary that may or may not be on a stalk.
There are 3 to 4 fused carpels and 3 to 4 stigmas either on a style or directly on the ovary.
The fruit is a berry.