Naio (Myoporum sandwicense) is an endemic plant that has a variety of forms, from ground cover to tree. The flower color can also vary quite a bit. I’ve seen pinkish purple blooms previously, but these flowers, on a shrubby plant, were all white. Naio used to be common in Hawaii, but now is much less so. It’s known as false sandalwood because the heartwood of the tree form smells similar to true sandalwood.
The butterfly in the top photo is a Western Pygmy Blue butterfly. a native of the Americas, it was first seen in Hawaii in 1978.