Primate World was originally planted in aspen and other native species. Over time the garden has taken on a more lush and tropical feel. Many of the plants have large and compound leaves. Much like Asian Highlands, this as a trial area for new and/or underutilized species. Kentucky Coffeetree (Gymnocladus dioicus) and Ohio Buckeye (Hippocastanum glabra) are both incredible trees that have found a home in PW. Unfortunately, they grow slowly and are often irregularly and sparsely branched when young, so they get passed by in nurseries by consumers. Kentucky Coffeetrees have pinnately compound leave and showy white flowers. They are dioecious, so the male and female flower part reside on separate trees; only the female trees will bear the large mahogany colored seed pods. Ohio Buckeyes have palmately compound leaves and yellowish green flowers. A non-edible buckeye forms and is protected by a spiny shell. Ashleaf Spirea, or Sorbaria sorbifolia, is one such plant that grows five to seven feet tall and has white flowers in late summer. It is extremely hardy and has proven to be very resilient inside animal enclosures.