would anyone please help me understand the following underlined sentence? I can't understand how a tree exists as four individuals. Euphorbia tanaensis is a poorly-known, medium-sized succulent tree, and a member of the large (2000 species) diverse plant genus Euphorbia. The tree stands up to 30 meters tall, and the single trunk reaches up to approximately 50 cm in diameter; typical of the Euphorbia its flowers are reduced and clustered into flowerheads called cyanthia. This species is thought to exist as just four mature individuals in a single deciduous swamp forest in the small (42 square km) Witu Forest Reserve of coastal Kenya. Thanks in advance.