Foster Botanical Garden in Honolulu, listed on the National Register of Historic Places, houses 24 of Oahu’s officially designated Exceptional Trees and features turfgrass species including Axonopus compressus, Axonopus affinus, and Paspalum conjugatum beneath its canopy. The Honolulu Botanical Gardens system also includes the Koko Crater Botanical Garden, where hot, dry conditions make it an ideal site for dryland plant collections.