My garden was previously landscaped in a typical Hilo Japanese style, but slowly I've been substituting native plants for the usual exotics. Though I like walking iris, I wanted to transition to something native and replaced it with native 'uki'uki, and it is doing extremely well. This planting is only 3 years old and doing extremely well in a partially shaded location next to a rock wall. It produces copious berries which I've shared with a student learning to make kapa -- 'uki'uki berries produce a blue dye which has been used traditionally. I've seen a beautiful piece of mamaki kapa with patterns in grey-blue 'uki'uki dye at the Honolulu Academy of Arts.
'Uki'uki, Dianella sandwicensis, is in the Lily family. It's easy to grow and virtually pest free as a grouping under trees. It also makes a great container plant. Try it in a hypertufa one you make yourself.