The Hawaiian island chain is isolated from other land masses. This isolation has allowed some unique species of flowers and flowering plants to evolve on the islands. With unusual native hibiscus, unique flowering shrubs, and low-growing orchids, Hawaii's tropical climate and ample rain create an ideal environment for many native flowers and plants. Some flowering plants do not grow outside of the island chain.
Kokio, or Hibiscus clayi, is a hibiscus native to Hawaii. It is sometimes called Clay's hibiscus. This type of native hibiscus is found in all parts of Hawaii and can grow as a tall shrub or small tree if not pruned. Unpruned kokio can reach between 10 and 30 feet with over a 5-foot spread. Kokio is often planted as a manicured shrub or hedge screen and can easily be cultivated in containers. The flowers of the Kokio are showy and range from medium red to dark red. These plants bloom all year and are usually in constant bloom. They require full or partial sun, need soil that drains well, and do not require a lot of irrigation. Kokio can grow well in USDA hardiness zones 10 and 11 and can grow in southern Florida, California, Texas or other places in zones 10 and 11.
Kanawao, or Broussaisia arguta, is a common shrub that grows in the understory of Hawaii's rain forests. An evergreen shrub that reaches 5 to 10 feet, the kanawao produces roundish flat clusters of flowers that reach between 2 inches wide and 4 1/2 inches wide. These clusters are comprised of many short-stalked flowers. Flowers on a particular plant are either male or female, meaning that kanawao is not self-fertilizing. These flowering bushes are common between 1,000 and 6,000 feet throughout the Hawaiian Islands. The kanawao is native to Hawaii and does not grow anywhere else. In some cases, you may be able to grow this plant in very carefully controlled greenhouse conditions in areas outside of Hawaii.
The jewel orchid, or Anoectochilus sandvicensis, is a ground-growing orchid that has thin, shiny green leaves and flowers on terminal spikes that range from green to yellow. Although rare, this species is found on all Hawaiian Islands except Niihau and Kahoolawe. It is most often found on Maui and Molokai. It is also frequently found on Oahu. This orchid creeps, making it hard to distinguish individual plants growing under natural conditions. The jewel orchid can grow in pots under normal orchid growing conditions.