African nutmeg

Monodora myristica is a tall tropical rainforest tree, up to about 35 metres in the wild, with large, drooping, orchid-like yellow and red flowers. It produces big, round, hard-shelled fruits, sometimes the size of a grapefruit or larger, which look like small gourds. Inside, the pulp holds numerous brown, ridged, pea-sized to olive-sized seeds.

The seeds are dried, and their hard shells are removed or cracked, then the kernels are toasted or ground. The scent is warm, sweet and peppery, resembling nutmeg and ginger with a hint of citrus. They are sold whole, cracked or ground, and sometimes labelled with the name ehuru or calabash nutmeg.

Monodora myristica is native to the rainforests and humid forest margins of West and Central Africa, from Sierra Leone through Nigeria and the Congo basin to Uganda and Angola. It was also taken to the Caribbean, where it grows in Jamaica and neighbouring islands and is called Jamaican nutmeg.

The species name myristica refers to its resemblance to true nutmeg, Myristica fragrans, although the two are not close relatives. The common name calabash nutmeg refers to the large, round, gourd-like fruit.

West African cooks have long used the seeds of the calabash nutmeg tree as a spice. In Nigeria, the Igbo call it ehuru and use it in pepper soups, particularly a spicy broth made for new mothers and for festive occasions, while Yoruba cooks use it as ariwo. In other regions, it is used to flavour stews, sauces, rice dishes and cakes in place of imported nutmeg.

The tree has also been valued in traditional medicine, with seeds, bark and roots used in remedies. European botanists collected specimens in the 19th century and described its resemblance to nutmeg, and the seeds reached Caribbean island markets where they were used as a nutmeg substitute.

Today, calabash nutmeg appears in African grocery stores around the world and is exported in modest quantities. Research has explored the seed's essential oil and phytochemistry, and interest in African culinary heritage is raising its profile among chefs. Deforestation and habitat loss are pressures on wild populations of the tree.

Ground or toasted seeds are used to season pepper soups, stews, sauces, rice, beans and meat dishes in West Africa, and some cooks add them to tea, porridge and baked goods. The whole seeds are sometimes strung as beads or used to make cosmetic oil.

In traditional remedies, the seeds, bark and roots are used in preparations for digestive and other complaints, and seed butter has been used in local cosmetic and skin treatments. Cooks often toast the kernels lightly in a dry pan first, which deepens the aroma before grinding them with chillies or other spices.

African nutmeg seeds contain an aromatic essential oil and various plant compounds that researchers have investigated for antioxidant and antimicrobial activity in the laboratory. Traditional uses include digestive support and use as a postpartum tonic, but there is not enough clinical evidence to support medical claims. As a spice used in small amounts, it adds flavour rather than significant nutrition.