Here is Koko Crater Botanical Garden on Oahu. Although many people think of Hawaii as tropical, there are some very dry areas, and this botanical garden has specimens from deserts and dry habitats all over the world. Plus some very pretty plumerias!
closeup of pink bougainvilleas
the cactus garden
some sort of air/cactus/parasitic plant hanging on a tree, completely covering the branches.
closeup of those plants
some sort of melon/seed pod thing, about the size of a softball