The vascular plant flora of the Cocos (Keeling) Islands consists of approximately 61 species native to the 22 vegetated islands and about 69 introduced species, most of which are confined to the two larger inhabited islands, Home Island and West Island. There are no plant species endemic to the islands; however, one variety of Pandanus tectorius, P. tectorius var. cocosensis, is only found growing on these islands. The native vegetation of the two atolls primarily consists of sea-dispersed shoreline plants of the Indo-Pacific region. On the lagoon shoreline, tall shrublands are dominated by Pemphis acidula and Cordia subcordata, often growing in monospecific stands. Closed forest stands are dominated by either Cocos nucifera or Pisonia grandis.Williams, D.G. 1994. Vegetation and flora of the Cocos (Keeling) Islands. Atoll Research Bulletin, 404: 1-29.
Much of the area of the southern islands has been modified for coconut plantations, altering the vegetation from the pre-settlement era. North Keeling, about to the north, has been protected as part of the Pulu Keeling National Park, where 31 plants can be found, of which six are introduced. About half of the species on the southern atoll are introduced.Claussen, J., and D. Slip. 2002. The status of exotic plants on the Cocos (Keeling) Islands, Indian Ocean. Parks Australia North, Department of the Environment. Accessed online: 13 May 2015.
In a report to Parks Australia in 2002, of the many introduced species on the southern atoll, Chromolaena odorata (Siam weed) was identified as being the greatest threat to the environment. Most of the introduced species are pantropical herbaceous plants likely introduced to the southern atoll after the airfield was built in 1944.
History The Cocos (Keeling) Islands are isolated, being the only atolls in the eastern Indian Ocean, and were uninhabited until relatively recently in the early 19th century. The first botanical study was done while naturalist Charles Darwin visited the southern atoll for ten days, arriving April 1, 1836. Darwin collected 21 species during his time on the islands.
Later, the Scottish botanist Henry Ogg Forbes botanised the southern islands in 1879, collecting 38 species in 22 days, followed by W. E. Birch in 1885 and the British botanist Henry B. Guppy, who spent ten weeks in 1888 on both atolls. By far the longest visit by a naturalist was that of Frederic Wood Jones who spent 15 months on the southern atoll in 1909 and published his account in the book, Coral and Atolls. A History and Description of the Keeling-Cocos Islands, with an account of their Fauna and Flora, and a Discussion of the Method of Development and Transformation of Coral Structures in General, published in 1912. The northern atoll was visited in 1941 by the British naturalist Carl Alexander Gibson-Hill, who provided the first systematic assessment of the plant communities and a description of the dominant flora. The 1980s saw the two largest surveys in 1985 by I. R. Telford, who collected 93 species from both atolls, and in 1986-1987 by D. G. Williams, who collected 130 from all islands.
Species Species Family Vernacular name Local name Status Image Dicliptera ciliata Acanthaceae native Sesuvium portulacastrum Aizoaceae sea purslane native Achyranthes aspera var. villosior Amaranthaceae chaff flower native Aerva lanata Amaranthaceae introduced Crinum asiaticum Amaryllidaceae crinum lily native Zephyranthes rosea Amaryllidaceae introduced Ochrosia oppositifolia Apocynaceae Kayu Laki native Cocos nucifera Arecaceae coconut Kelapa native Austroeupatorium inulaefolium Asteraceae stinkweed introduced Chromolaena odorata Asteraceae Siam weed introduced Cyanthillium cinereum Asteraceae introduced Eleutheranthera ruderalis Asteraceae introduced Emilia sonchifolia Asteraceae introduced Erigeron bonariensis Asteraceae fleabane introduced Sonchus oleraceus Asteraceae milk thistle introduced Synedrella nodiflora Asteraceae introduced Tridax procumbens Asteraceae introduced Wollastonia biflora Asteraceae beach sunflower native Argusia argentea Boraginaceae octopus bush Kayu Sireh native Cordia subcordata Boraginaceae sea trumpet Geronggang native Lepidium virginicum Brassicaceae introduced Caesalpinia bonduc Caesalpiniaceae nickernut Kelenchi native Senna occidentalis Caesalpiniaceae introduced Calophyllum inophyllum Calophyllaceae Alexandrian laurel Nyamplong native Hippobroma longiflora Campanulaceae introduced Carica papaya Caricaceae pawpaw Katis introduced Casuarina equisetifolia subsp. equisetifolia Casuarinaceae coastal sheoak Cemara native Cleome gynandra Cleomaceae native Terminalia catappa Combretaceae sea almond Ketapang native Tradescantia spathacea Commelinaceae introduced Ipomoea violacea Convolvulaceae moon flower native Ipomoea pes-caprae Convolvulaceae goat's-foot Kangkong Meryap native Bryophyllum pinnatum Crassulaceae introduced Syringodium isoetifolium Cymodoceaceae sea grass native Thalassodendron ciliatum Cymodoceaceae sea grass native Cyperus bulbosus Cyperaceae nut grass native Cyperus javanicus Cyperaceae native Cyperus polystachyos Cyperaceae introduced Fimbristylis cymosa Cyperaceae native Queenslandiella hyalina Cyperaceae native Acalypha indica Euphorbiaceae native Acalypha lanceolata Euphorbiaceae native Euphorbia atoto Euphorbiaceae native Euphorbia cyathophora Euphorbiaceae dwarf poinsettia introduced Euphorbia hirta Euphorbiaceae introduced Euphorbia prostrata Euphorbiaceae introduced Ricinus communis Euphorbiaceae castor oil plant Pokok Jaru Jarak introduced Alysicarpus vaginalis Fabaceae introduced Canavalia cathartica Fabaceae sea bean native Crotalaria retusa Fabaceae introduced Desmodium triflorum Fabaceae introduced Erythrina variegata Fabaceae coral tree Kayu Dedap native Indigofera hirsuta Fabaceae introduced Leucaena leucocephala Fabaceae leucaena Peteh introduced Macroptilium atropurpureum Fabaceae siratro introduced Sesbania cannabina Fabaceae introduced Sesbania grandiflora Fabaceae Turi introduced Vigna marina Fabaceae native Enicostema axillare subsp. littorale Gentianaceae native Scaevola taccada Goodeniaceae sea lettuce Kayu Kankong native Hernandia nymphaeifolia Hernandiaceae sea hearse Kayu Jambu Hutan native Thalassia hemprichii Hydrocharitaceae sea grass native Clerodendrum indicum Lamiaceae introduced Vitex trifolia Lamiaceae native Volkameria inermis Lamiaceae sorcerer's flower native Cassytha filiformis Lauraceae devil's twine native Barringtonia asiatica Lecythidaceae box fruit Kayu Besagi native Pemphis acidula Lythraceae Kayu Keriting native Hibiscus tiliaceus Malvaceae cotton tree Pokok Waru native Sida acuta Malvaceae introduced Thespesia populnea Malvaceae portia tree Waru Hutan native Triumfetta repens Malvaceae Bingit burr native Muntingia calabura Muntingiaceae Buah Cheri introduced Eugenia sp. Myrtaceae Jambu Ayer introduced Psidium guajava Myrtaceae guava Jambu Biji introduced Boerhavia albiflora Nyctaginaceae introduced Boerhavia diffusa Nyctaginaceae introduced Boerhavia repens Nyctaginaceae native Pisonia grandis Nyctaginaceae pisonia Ampol native Ximenia americana Olacaceae yellow plum Rukam native Striga angustifolia Orobanchaceae introduced Pandanus tectorius var. cocosensis Pandanaceae screw palm Pandan native Passiflora foetida var. hispida Passifloraceae stinking passionflower introduced Turnera ulmifolia Passifloraceae introduced Breynia disticha Phyllanthaceae introduced Phyllanthus amarus Phyllanthaceae native Sauropus androgynus Phyllanthaceae Keretu introduced Rivina humilis Phytolaccaceae coral berry introduced Scoparia dulcis Plantaginaceae introduced Apluda mutica Poaceae introduced Bothriochloa bladhii Poaceae introduced Brachiaria brizantha Poaceae introduced Cenchrus ciliaris Poaceae introduced Cenchrus echinatus Poaceae sand burr introduced Chloris barbata Poaceae introduced Chrysopogon aciculatus Poaceae introduced Cynodon dactylon Poaceae couch grass introduced Cynodon radiatus Poaceae introduced Dactyloctenium aegyptium Poaceae introduced Desmostachya bipinnata Poaceae introduced Digitaria setigera Poaceae introduced Eleusine indica Poaceae crowsfoot grass introduced Eragrostis amabilis Poaceae introduced Eriochloa meyeriana Poaceae introduced Imperata cylindrica var. major Poaceae bladey grass introduced Ischaemum muticum Poaceae introduced Lepturopetium sp. aff. marshallense Poaceae native Lepturus repens Poaceae stalky grass native Panicum repens Poaceae introduced Paspalum vaginatum Poaceae native Sporobolus fertilis Poaceae sand couch grass introduced Stenotaphrum micranthum Poaceae beach buffalo grass native Thuarea involuta Poaceae bird's-beak grass native Zoysia matrella Poaceae native Unidentified sp. Poaceae introduced Portulaca oleracea Portulacaceae pigweed native Rhizophora apiculata Rhizophoraceae spider mangrove native Guettarda speciosa Rubiaceae Kembang Melati Hutan native Morinda citrifolia Rubiaceae cheesefruit Mengkudu native Oldenlandia corymbosa Rubiaceae introduced Spermacoce remota Rubiaceae introduced Triphasia trifolia Rutaceae Buah Kengkit introduced Allophylus cobbe Sapindaceae native Dodonaea viscosa Sapindaceae hopbush native Physalis minima Solanaceae Chepelok introduced Solanum americanum Solanaceae blackberry nightshade introduced Suriana maritima Surianaceae native Laportea aestuans Urticaceae native Phyla nodiflora Verbenaceae introduced Premna serratifolia Verbenaceae native Stachytarpheta jamaicensis Verbenaceae blue snakeweed introduced
See also Fauna of the Cocos (Keeling) Islands
References
External links Flora of Pulu Keeling National Park. Department of the Environment, Australian Government.