We spent Thanksgiving weekend visiting Guy's nephew in Oahu. We visited the Koko Crater Botanical Garden in the southeast corner of the island, about 10 miles east of Diamond Head, and a mile north of Hanauma Bay (as the nene flies).
This is a dry landscape in a southern rainshadow. The garden is young, admission is free, and tours are self-guided. The collection features bouganvillea, plumeria, dryland palms, cacti, cycads, and a grove of young baobab trees (among other things). Many of the most of the interesting specimens have accession tags.
Here are some pictures.
Here is the plumeria's fruit--elongated capsules, 10 inches long--but I still can't figure out the sex parts.
Euphorbia milii. You can grow this outdoors in San Francisco (and I do), but it's so much more impressive in low desert gardens.
Agave attenuata. I was surprised to see this plant all over Oahu, because I've never seen it in Kauai (the Hawaiian island I visit most often).
What looked like some Euphorbia hung from trees like Spanish Moss.
This went on for acres.
(Note Nolina texana in the background.)
Even small baobabs (Adansonia) make very impressive specimens, and Koko Crater has dozens.
I'll be excited come back here every few years to monitor their progress.
A couple days later we visited the Foster Botanical Garden, Hawaii's crown jewel of botanic gardens.