Kamakahala
Kamakahala usually occurs at the summit on Oahu. I seen on both Waianae and Koolau mountain ranges. It is difficult to identify the plant when it is not flowering, however it is super easy to tell when flowering.
Background Information
There are 15 endemic species of Kamakahala. It is in the logania family. I'm not sure about the Ancient Hawaiian uses. It grows as ground cover or a shrub. As mentioned, I've only seen it on the summits both Waianaes and Ko'olaus.
Kamakahala
This is a rare species of Kamakahala. Located in the Northern and Central Ko'olaus only, its name is labordia hosakana. It is listed as federally endangered with not more than 200 plants remaining in the wild.
Kamakahala
This Kamakahala was found in the Northern KST. The blooming period seems to be in April & May and possibly other months of the year. This species could be labordia fagraeoides as this particular species occurs in the Ko'olau Mountains.
Kamakahala
This species appears to be labordia waiolani. But again it is hard to tell what this particular species is as Kamakahala crosses with other Kamakahala.
Ka'ala Bog in June 2018
Sources:
Flowering Plants of Hawaii, 852-864
Hawaiian Plant Life, 118-120