Pohinahina
Pohinahina is common on Oahu. You'll see it a lot in landscaping. It is easy to grow with beautiful purple flowers. Many native gardens have Pohinahina.
Background Information
This indigenous species is found all on the main islands except Kaho'olawe. The common name is Beach Vitex. Ancient Hawaiians used the plant for medicinal purposes. In modern times, the plant is used a lot for landscaping because it easily grows in dry conditions.
Pohinahina
The leaves of Pohinahina are round, white hairy beneath, pattern. The flowers are purple.
Kalaeloa Beach Park 2018
Source
Hawaiian Plant Life, 117