Flowers and Fruits

The distinctive flowers of Cola nitida are cream-white to yellow with red stripes. Both sexes are found on the same tree and are capable of self-pollination. The fertilized flowers develop into bean-shaped fruits, about the size of an adults hand, with a thick, leathery shell. They are arranged in a star-shape and contain 5-12 seeds that are deep red, pink, or cream-white.

Ants protect the fruits from pests by spinning webs around them. Nevertheless, the kola nut has enemies such as the kola beetle, moth larvae, and a type of mistletoe. 

Flowers

The flowers of Cola nitida have five cream-white to yellow petals with red stripes. In the male flowers, the stamens with pollen sacs are located in the center of the flower, while the female flowers have a pistil. These are larger and fewer in number than their male counterparts.

Both sexes occur on the same tree (monoecious) and can self-pollinate to increase the odds of survival and spreading of the kola. However, the seeds produced become infertile after several generations without genetic exchange.

Fruits

The fertilized flowers develop into five fruits arranged in a star-shape with a dark green, thick, and leathery shell. These follicle fruits are also called aggregate fruits. The inner seeds have a fleshy seed coat, also called aril or sarcotesta. The seeds do not contain endosperm, and the embryo of Cola nitida usually has two cotyledons. Other Cola species can have up to seven cotyledons.

When the kola fruit is opened up, usually with a machete, 5-12 chestnut-sized, deep red, pink, or cream-white seeds in a white skin, the seed coat, become visible. This skin can be easily removed after about 15 minutes of soaking in cold water, revealing the colorful and caffeine-containing seeds.

Beneficial Insects, Pests, and Parasites

Ants protect the fruits of the kola trees during their ripening by catching harmful insects and feeding on them. They often build their nests in the forks of the branches and are numerous on the trees, where they spin webs around the fruits to catch pests. This symbiosis between ants and kola trees is particularly remarkable and can be observed in Ghana.

Nevertheless, the kola nut has some successful enemies. These include Balanogastris kolae, the kola beetle, Characoma strictigrapta, a moth (or its larvae), and Sahlbergella, a beetle species that usually infests cocoa but also attacks the related kola.

Additionally, mistletoes grow in the branches of the trees. These plants, known as "Krampas" in Ghana, are thoroughly cut out of the trees because they sap all the strength from the tree and cause harvest failures.