Native caper  (Capparis sandwichiana)

Classified as Vulnerable (VU) on the IUCN Red List (1).

This native caper is a woody, sprawling shrub that starts growing along the ground but then becomes upright (2). The leaves are light green and oval-shaped and bear short, fine hairs when young, but are hairless when older (2) (3). The solitary, white, lemon-fragranced flowers, which measure up to ten centimetres wide and ten centimetres tall, open after sunset (2). A profusion of long, delicate, white stamens protrude from the four large, white, orchid-like petals, endowing this flower with an ethereal beauty (2). At daybreak, the petals and stamen become tinged with pink and wilt, enhancing the plant’s enchanting allure (2).

The native caper is endemic to the Hawaiian Islands, where it occurs on the islands of Kauai, Kaho’olawe, Oahu, Ni’ihau, Molokai, Maui, Lanai and Hawaii, as well as the atolls of Midway, Pearl and Hermes, and Laysan (1). While rare over most of its range, the native caper is said to be common along parts of the Kona coast on the island of Hawaii (3).

The native caper occurs in dry regions, most commonly in coastal areas, where it grows on lava rock, cliffs, emerged coral reefs, and in rocky ravines (1).

The beautiful flowers of the native caper typically bloom in the spring and summer months (4), and are then pollinated by native moths which feed on the flowers’ nectar at night. Once the flowers are pollinated, small cucumber-like fruits, measuring five to six centimetres long, begin to develop. The fruit, which is filled with bright orange pulp and several small, brownish-black seeds, is fed upon by a number of bird species (5).

Interestingly, in the past the native caper was used as a medicine for broken bones (6), and milky sap from the plant was used with other ingredients to treat boils (7).

The native caper has been adversely affected by many factors threatening the dry coastal areas it inhabits. This includes the development of coastal regions, the conversion of land for agriculture and ranching, and fire. Trampling and grazing by livestock and invasive alien plants are also threatening the survival of this species (3).

In August 2007, more than 800 native caper plants were planted in areas cleared of invasive weeds, such as kiawe (Prosopis pallida) and koa haole (Leucaena leucocephal), as part of a coastal restoration project. The team that undertook the work hope to return this site to the way it might have looked centuries ago (8). More areas need to be restored if future of this beautiful plant is to be secured (8).

To learn more about conservation efforts in the Hawaiian Islands see:

• Hawaii Plant Extinction Prevention Program:
  http://hawaiipepp.blogspot.com
• Island Conservation:
  http://www.islandconservation.org/where/?id=28
• Hawai’i Wildlife Fund:
  http://wildhawaii.org