Chocolate lowland climate in the narrow band of latitudes where cacao is grown (20 degrees north and south of the equator), the commercial company Mars, Incorporated and the University of California, Berkeley are conducting genomic research in 2017–18 to improve the survivability of cacao plants in hot climates. Chocolate is made from cocoa beans, the dried and fermented seeds of the cacao tree ("Theobroma cacao"), a small, 4–8 m tall (15–26 ft tall) evergreen tree native to the deep tropical region of the Americas. Recent genetic studies suggest the most common genotype of the plant originated in the Amazon basin and
North-West University Botanical Garden rockery. Some more common plant genera represented in the garden include Acacia, Aloe, Bonatea, Crinum, Dierama, Encephalartos, Eucomis, Eulophia, Euphorbia, Gasteria, Gladiolus, Haworthia, Hypoxis, Indigofera, Kniphofia, Plectranthus, Podocarpus, Polygala, Scadoxus, Searsia, Stapelia and Zantedeschia. In the tropical greenhouse a variety of tropical and subtropical plants from all over the world can be found. Some of the plants include a variety of food and medicinal plants including "Coffea arabica" (coffee), "Camellia sinensis" (tea), "Vanilla planifolia" (vanilla), "Saccharum officinarum" (sugarcane), "Cinnamomum zeylanicum" (cinnamon), "Oryza sativa" (rice), "Theobroma cacao" (cacao), "Siphonochilus aethiopicus" (wild ginger), "Warburghia salutaris" (pepper bark tree) and "Piper nigrum" (pepper).