Kapāpala is a small calcareous islet about 9.5 acres in size and reaches a height of 14 ft. Kapāpala island is located in Kaneohe bay approximately 2 miles offshore in the south central portion of the bay, north of Kekepa islet. The outer edges are sharp limestone and lithified dune outcrops with some sandy sections in the interior. The islet is accessible to the public with very little restrictions. Despite the lack of restrictions, many native plants still exist, mostly away from human dominated areas and near the ocean where native plants have a competitive advantage in the harsh salty conditions.

The islet is mostly made up of native species, especially near shore areas. Akulikuli (Sesuvium portulacastrum) and akiaki (Sporobolus virginicus) are found closest to the ocean. There are also a few milo (Thespesia populnea), mostly near the ocean on the southwest side. There are healthy patches of alena (Boerhavia repens) throughout the islet, several hinahina (Heliotropium anomalum var. argenteum) patches on the southeast side near the coast, and large patches of akiaki (Sporobolus virginicus), mostly near the margins. Scattered naupaka patches were observed over most of the islet. Central areas were mostly made up of ilima (Sida fallax), alena (Boerhavia repens) and pau o Hiiaka (Jacquemontia ovalifolia subsp. sandwicensis). On the south shore, there are some small patches of koali awa (Ipomoea indica) and kaunaoa (Cuscuta sandwichiana). Ihi (Portulaca lutea) can be seen in some coastal areas. A few areas of non-native vegetation exists, such as near the landing, along the south shore, and in the central area. Bermuda grass (Cynodon dactylon) lawns were found just above the beach and along the south shore near the landing area. There was also some khaki weed (Alternanthera pungens) and New Zealand spinach (Tetragonia tetragonioides). Ironwood (Casuarina glauca) dominates the central area. Near the fishing shrine where ironwood was cleared from is a patch of sourbush (Pluchea spp.) and Spanish needles (Bidens alba var. radiata). Near the coast are a few sea grape and beach heliotrope (Tournefortia argentea). There is a small patch of pickle weed (Batis maritima) on the south side near the coast.