Forests and woodlands cover 43 percent of the state’s total land area. Grasslands and pasture cover 25 percent. The plant life of Hawaii is distinguished by its great variety of both native and introduced species and by the remarkably large number of plants that are endemic, or unique, to the island chain. It is likely that Hawaii’s native vegetation, which flourished on the islands long before the first Polynesian settlers arrived, evolved from relatively few plants. These came from seeds and spores carried to the islands by wind, water, and birds. Common native trees include ohia, hala, and koa.
The Polynesians brought with them such useful food plants as the coconut, breadfruit, sweet potato, yam, banana, sugarcane, arrowroot, and taro. They also introduced several trees, among them the candlenut, or kukui, which is the state tree, the mountain or Malay apple, and the paper mulberry.
Since the arrival of Europeans and Americans numerous kinds of trees, shrubs, and especially exotic flowers have been introduced. These species have included pines and mesquite from North America, eucalyptus from Australia, frangipani (plumeria) and guava from tropical America, Bermuda grass from southern Europe, and gorse from western Europe. The introduced species now form important and even dominant elements in the islands’ vegetation. The great profusion of wildflowers in Hawaii includes native species, introduced species, and new crossbred combinations. In addition to the more than 5,000 varieties of the hibiscus, there are hundreds of kinds of orchids. All but a few of these orchids are alien species, meaning they were introduced to Hawaii by humans. Torch gingers, jacarandas, bauhinia, and poinsettias are among many other ornamental species that also flourish.
The islands can be divided into a series of vegetation zones. The low, dry coastal flats and the lower mountain slopes on the leeward side of the islands are now dominated by alien plants such as mesquite, koa haole, cactus, drought resistant grasses, and occasionally by two native trees, the wiliwili and the naio, or bastard sandalwood. The introduced coconut palm is common along some beaches. Higher up the leeward slopes this zone merges with a so-called dry forest zone where the most common tree is the kukui, the state tree. Koa haole, lantana, cactus, and alien weedy species form dense thickets interspersed with grasses in this zone. Niihau and Kahoolawe lie entirely within these two zones.
Still higher up on the leeward slopes and extending upward from sea level on the windward slopes lies a more humid forest zone, where the principal trees are the ohia and the koa and the undergrowth is dense and luxurious. There is a zone of rain forest where the annual rainfall exceeds 1,500 mm (60 in). The rain forest includes the leeward slopes of Hawaii and Maui between 1,200 and 2,400 m (4,000 and 8,000 ft), and the region extending upward from near sea level on the wetter windward slopes. In this zone the ohia is associated with giant tree ferns, lobelias, and many other native species.
On Hawaii and Maui alone, there are two zones above the rain forest zone, where the trees thin out as the climate grows drier and colder. Above the timberline, about 3,000 m (about 10,000 ft) above sea level, lies a zone of desertlike high elevation vegetation of low, scrubby plants and scattered grasses. Among the five endemic species of Hawaiian silversword plants, one is a rare and spectacular plant found only near the summit of Haleakala on Maui, and on high mountains on Hawaii. It has long, curved, succulent leaves with tiny white hairs that give the plant a silver appearance. Once during its lifetime it sends forth a tall stalk with hundreds of blossoms, and then it dies. Above this zone, on the upper slopes of Mauna Loa and Mauna Kea, there is a dry, barren alpine zone devoid of vegetation except for mosses and lichens. "Hawaii" © Emmanuel BUCHOT, Encarta, Wikipedia
Photos of European countries to visit
Photos of Asian countries to visit
Photos of America