Hawaii is so floriferous that it would be easy to overlook plants that disappear. Fortunately, organizations such as the Center for Plant Conservation (CPC) keep track of the numbers of rare plants. Once considered endangered, programs to protect and cultivate scarce species go into place. Plants decline due to habitat destruction. This can be caused by construction, weather, pollution and even unlawful plant collecting.
Abutilons, flowering perennials, are called flowering maples because the leaves are palmate. There is no relation to maples trees. They are a sparse plant with bell-shaped flowers. There are three Hawaiian species of flowering maples listed as endangered. Both Abutilon eremitopetalum and Abutilon menziesii develop red flowers. The third, Abutilon sundwieense, has an unusual green flower with a yellow center. The Hawaiian name for abutilon is KO' Oloa Ula.
Two native species of Hawaiian gardenia are in danger. Gardenia brighamii has been stepped up to the critically endangered list, and a recovery plan is being developed. These native shrubs are tree-like and can reach 15 feet tall and live up to 65 years. Another scarce species is Gardenia mannii. Both plants have flowers with single white petals. Unlike modern shrub varieties, these gardenias are found on slopes and hillsides at higher elevations.The Hawaiian name for gardenia is Nanu.
Many of the hibiscus seen growing in Hawaii are Chinese hibiscus. But Hawaii boasts its own native species. There are three hibiscus that are considered rare. Hibiscus arnottianus immaculatus has a beautiful large white flower with red stamens. It is one of the few fragrant species. Hibiscus brackenridgei has a bright yellow flower and is Hawaii's state flower. Hibiscus clayi has a vibrant red flower. The Hawaiian name for hibiscus is Koki'oke'o.
Violets are unexpected among the flora and fauna of Hawaii's woodlands. Most bear similarities to common violets, but are larger and often woody plants. Three endemic species have been placed on the endangered list. Viola lunaiensis has a pale pink to white flower. Viola chamissoniana has a pale pink flower with very long petals. Viola oahuensis has a pure white flower and larger leaves. This one is found high in the mountains of Oahu. The Hawaiian name for violet is Lolana.
Hawaii has two endangered geranium species. Geranium arboreum is also called the red flowering geranium. This flower is found on the island of Maui. It is an unusual shrub-type of geranium. Also rare is Geranium multiflorum, which is an endemic species with white petals. The Hawaiian name for geranium is Nohoanu.
There are only three native species of orchid among the Hawaiian islands. One of the three, fringed orchid (Plantanthera holochita), can no longer be found on the island of Kauai. A hurricane destroyed the existing population there. This orchid produces flower spikes of creamy-green narrow tubular flowers. There is still a small number of these rare orchids on the islands of Maui and Molokai.