Alligator pepper (also known as mbongo spice, hepper pepper) is a West African spice which corresponds to the seeds and seed pods of Aframomum danielli, Aframomum citratum or Aframomum exscapum. It is a close relative of grains of paradise, obtained from the closely-related species, Aframomum exscapum. However, unlike grains of paradise which are generally sold as only the seeds of the plant, Alligator pepper is sold as the entire pod containing the seeds (in the same manner to another close relative, black cardamom).
The plants which provide alligator pepper are herbaceous perennials of the ginger (Zingiberaceae) family of flowering plants that are native to swampy habitats along the West African coast. Once the pod is open and the seeds are revealed the reason for this spice's common English name becomes apparent as the seeds have a papery skin enclosing them and the bumps of the seeds within this skin is reminiscent of an alligator's back.
As mbongo spice the seeds of alligator pepper is often sold as the grains themselves, isolated from the pod and with the outer skin removed. Mbongo spice is most commonly either Aframomum danielli or Aframomum citratum and has a more floral aroma than Aframomum exscapum (which is the commonest source of the entire pod).
It is a common ingredient in West African cuisine where it imparts both 'heat', 'pungency' and a spicy aroma to classic West African 'soups' (stews).