Flora of Hawaii (Hawaii pt 5)

by Jim Morgan



Flora. The Hawaiian Islands have a peculiar flora. As a result of their isolation, the proportion of endemic plants is greater here than in any other region, and the great elevation of the mountains, with the consequent variation in temperature, moisture and barometric pressure, has multiplied the number of species. Towards the close of the 19th century William Hillebrand found 365 genera and 999 species, and of this number of species 653 were peculiar to this part of the Pacific. The number of species is greatest on the older islands, particularly Kauai and Oahu, and the total number for the
group has been constantly increasing, some being introduced, others possibly being produced by the varying climatic conditions from those already existing. Among the peculiar dicotyledonous plants there is not a single annual, and by far the greater number are perennial and woody. Hawaiian forests are distinctly tropical, and are composed for the most part of trees below the medium height. They are most common between elevations of 2000 and 8000 ft. ; there are only a few species below 2000 ft., and above 8000 ft. the growth is stunted. The destruction of considerable portions of the forests
by cattle, goats, insects, fire and cutting has been followed by reforesting, the planting of hitherto barren tracts, the passage of severe forest fire laws, and the establishment of forest reserves, of which the area in 1909 was 545,746 acres, of which 357,180 were government land. In regions of heavy rainfall the ohia-lehua (Metrosideros polymorpha), a tree growing from 30 to 100 ft. in height, is predominant, and on account of the dense undergrowth chiefly of ferns and climbing vines, forms the most impenetrable of the forests; its hard wood is used chiefly for fuel. The koa (Acacia koa), from
the wood of which the natives used to make the bodies of their canoes, and the only tree of the islands that furnishes much valuable lumber (a hard cabinet wood marketed as ” Hawaiian mahogany “), forms extensive forests on Hawaii and Maui between elevations of 2000 and 4000 ft. The mamane (Sophora chrysophytta) , which furnishes the best posts, grows principally on the high slopes of Mauna Kea and Hualalai. Posts and railway ties are also made from ohia-ha (Eugenia sandwicensis). In many districts between elevations of 2000 and 6000 ft., where there is only a moderate amount of moisture, occur mixed forests of koa, koaia (Acacia koaia), kopiko (Straussia oncocarpa and 5. hawaiiensis) , kolea (Myrsine kauaiensis and M. lanaiensis), naio or bastard sandalwood (Myoporum sandwicense) and pua (Olea sandwicensis); of these the koaia furnishes a hard wood suitable for the manufacture of furniture, and out of it the natives formerly made spears and fancy paddles. The wood of the naio when dry has a fragrance resembling that of sandalwood, and is used for torches in fishing. The kukui (Aleurites triloba) and the algaroba (Prosopis juliflora) are the principal species of forest trees that occur below elevations of 2000 ft. The kukui grows along streams and gulches; from its nuts, which are very oily, the natives used to make candles, and it is still frequently called the candlenut tree. On the leeward side, from near the sea level to elevations of 1500 ft., and on ground that was formerly barren, the algaroba tree has formed dense forests since its introduction in 1837. Forests of iron-wood and blue gum have also been planted. Sandalwood (Sanlalum album or freycinetianum) was once abundant on rugged and rather inaccessible heights, but so great a demand arose for it in China, 1 where it was used for incense and for the manufacture of fancy articles, that the supply was nearly exhausted between 1802 and 1836; since then some young trees have sprung up, but the number is relatively small. Other peculiar trees prized for their wood are: the kauila (Alphitonia ponderosa), used for making spears, mallets and other tools; the kela (Mezoneuron kauaiense), the hard wood of which resembles ebony; the halapepe (Dracaena OMreo), out of the soft wood of which the natives carved many of their idols; and the wiliwili (Erythrina monosperma), the wood of which is as light as cork and is used for outriggers. In 1909, on six large rubber plantations, mostly on the windward side of the island of Maui, there were planted 444,450 ceara trees, 66,700 hevea trees, and 600 castilloa trees. About the only indigenous fruit-bearing plants are the Chilean strawberry (Fragaria chilensis) and the ohelo berry (Vaccinium reticulatum) , both of which grow at high elevations on Hawaii and Maui. The ohelo berry is famous in song and story, and formerly served as a propitiatory offering to Pele. The number of fruit-bearing trees, shrubs and plants that have been introduced and are successfully cultivated or grow wild is much greater; among them are the mango, orange, banana, pineapple, coconut, palm, grape, fig, strawberry, litchi (Nephelium litchi) the favourite fruit of the Chinese avocado or alligator pear (Persea gratissima), Sapodilla pear (Achras sapota), loquat or mespilus plum (Eriobotrya japonica) , Cape gooseberry (Physalis peruviana), tamarind (Tamarindus indica), papaw (Carica papaya), resembling in appearance the cantaloupe, granadilla (Passiflora quadrangularis) and guava (Psidiumguajava). Most of the native grasses are too coarse for grazing, and some of them, particularly the hilo grass (Paspalum conjugatum) , which forms a dense mat over the ground, prevent the spread of forests. The pili grass (Heteropogon contortus) is also noxious, for its awns get badly entangled in the wool of sheep. The native manienie (Slenotaphrum americanum) and kukai (Panicum pruriens), however, are relished by stock and are found on all the inhabited islands; the Bermuda grass (Cynodon dactylon), a June grass (Poa annua), and Guinea grass (Panicum iumentorum) have also been successfully introduced. The Paspalum orbiculare is the large swamp grass with which the natives covered their houses. On the island of Niihau is a fine grass (Cyperus laevigatus) , out of which the beautiful Niihau mats were formerly made; it is used in making Panama hats. Mats were also made of the leaves of the hala tree (Pandanus odoratissimus). The wauke plant (Broussonetia papyrifera), and to a less extent the mamake (Pipturus albidus) and Boehmeria stipularis, furnished the bark out of which the famous kapa cloth was made, while theolopa ( Cheirodendron gaudichaudi i) and the koolea (Myrsine lessertiana) furnished the dyes with which it was coloured. From several species of Cibotium is obtained a glossy yellowish wool, used for making pillows and mattresses. Ferns, of which there are about 130 species varying from a few inches to 30 ft. in height, form a luxuriant undergrowth in the ohia-lehua and the koa forests, and the islands are noted for the profusion and beautiful colours of their flowering plants. Kalo (Colocasia antiquorum, var., esculenta), which furnishes the principal food of the natives, and sugar cane (Saccharum officinaruni), the cultivation of which has become the chief industry of the islands, were introduced before the discovery of the group by Captain Cook in 1778. Sisal hemp has been introduced, and there is a large plantation of it W. of Honolulu.

Over seventy varieties of seaweeds, growing in the fresh-water pools and in the waters near the coast, are used by the natives as food. These limus, as they are called by the Kanakas, are washed, salted, broken and eaten as a relish or as a flavouring for fish or other meat. The culture of such algae may prove of economic importance; gelatine, glue and agar-agar would be valuable by-products.

1 The Chinese name for the Hawaiian Islands means ” Sandalwood

Text taken from the 11th Edition of the Encyclopaedia Brittanica Volume XIII pp 83-93. The 11th Edition of the Encyclopaedia Brittanica is in the public domain.