Endemic flora of Trinidad and Tobago

The endemic flora of Trinidad and Tobago includes a total of 59 species of vascular plants belonging to 34 plant families. This is less than 3% of the total vascular plant flora of Trinidad and Tobago. Thirty-nine of these species are endemic to Trinidad, 12 are Tobagonian endemics, and six are present on both islands.[1]

Island systems tend to be rich centres of endemism as a result of their isolation. The islands of the Greater Antilles have rates of endemism which range from 12 to 50% of their flora.[2] Trinidad and Tobago has a far lower rate of endemism, probably as a result of its geological history. The islands of Trinidad and Tobago lie on the South American continental shelf, and were both connected to the mainland during the Pleistocene. Tobago was separated from the mainland about 13,000 years ago; Trinidad was connected until more recently, and may only have become separated about 1,500 years ago.[1]

The flora of Trinidad and Tobago has been estimated to include about 2,500 vascular plant species.[1] Although historically as many as 222 species were thought to be endemic, a study by Veerle Van den Eynden and colleagues at the University of the West Indies found that only 59 of these species could validly be considered endemic, including eight species which they were unable to positively confirm as either endemic or non-endemic.[1]

Conservation status of endemic species

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Trinidad and Tobago is a small (5,126 km2), densely populated country. In addition, most endemic species are known from a relatively small number of localities—only eight of the 59 species are known from 5 or more localities.[1] In addition to this, 22 of these species have not been collected since 1958, and one that was last collected between 1786 and 1791.[1] Using the IUCN Red List criteria, 18 species have been classified as critically endangered, 16 as endangered, 15 as vulnerable, three as near threatened and three as data deficient. Only four endemic plant species were classified as being of least concern.[1]

Concentrations of endemic species

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Three areas in Trinidad and Tobago support relatively large numbers of endemic species—ridge-tops in the Northern Range, and savannas in Trinidad, and the Main Ridge in Tobago.[1]

List of endemic species

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Family Species Trinidad Tobago Conservation status
Acanthaceae Dicliptera aripoensis (Britton) Leonard X CR
Acanthaceae Justicia flaviflora (Turrill) Wassh. X CR
Acanthaceae Justicia tobagensis (Urb.) Wassh. X VU
Acanthaceae Odontonema brevipes Urb. X VU
Annonaceae Duguetia tobagensis (Urb.) R.E.Fr. X VU
Apocynaceae Cynanchum freemani (N.E.Br.) Woodson X EN
Apocynaceae Gonolobus tobagensis Urb. X X NT
Araceae Philodendron simmondsii Mayo X EN
Aristolochiaceae Aristolochia boosii Panter X EN
Asteraceae Mikania broadwayi B.L.Rob. X CR
Begoniaceae Begonia eciliata O.E.Schulz. X CR
Begoniaceae Begonia mariannensis Wassh. & McClellan X VU
Bromeliaceae Aechmea downsiana Pittendr. X CR
Bromeliaceae Werauhia broadwayi (L.B.Sm.) J.R.Grant X X NT
Burmanniaceae Marthella trinitatis (Johow) Urb. X CR
Celastraceae Maytenus monticola Sandwith X X LC
Celastraceae Maytenus reflexa Urb. X DD
Clusiaceae Clusia aripoensis Britton X EN
Clusiaceae Clusia intertexta Britton X CR
Clusiaceae Clusia tocuchensis Britton X EN
Cucurbitaceae Sicana trinitensis Cheesman X EN
Cyclanthaceae Dicranopygium insulare (Gleason) Harling X VU
Cyperaceae Rhynchospora aripoensis Britton X CR
Cyperaceae Rhynchospora ebracteata (Standl.) H.Pfeiff. X VU
Cyperaceae Rhynchospora ierensis C.Adams X EN
Cyperaceae Scleria orchardii C.Adams X CR
Eriocaulaceae Eriocaulon caesium Griseb. X CR
Euphorbiaceae Acalypha grisebachiana (Kuntze) Pax & K.Hoffm. X CR
Euphorbiaceae Croton aripoensis Philcox X CR
Euphorbiaceae Phyllanthus acacioides Urb. X VU
Euphorbiaceae Phyllanthus mimicus G.L.Webster X CR
Fabaceae Macrolobium trinitense Urb. X EN
Flacourtiaceae Xylosma sanctae-annae Sleumer X X EN
Gesneriaceae Besleria seitzii Krug & Urb. X VU
Gesneriaceae Besleria strigillosa Urb. ? ? DD
Lauraceae Ocotea trinidadensis Kosterm. X VU
Loranthaceae Phoradendron hartii Krug & Urb. X EN
Marcgraviaceae Marcgravia elegans Krug & Urb. X EN
Myrsinaceae Cybianthus cruegeri Mez X EN
Myrsinaceae Cybianthus pittieri Agostini X VU
Myrtaceae Eugenia cruegeri Krug & Urb. ex Urb. X X LC
Orchidaceae Cochleanthes trinitatis (Ames) R.E.Schult. & Garay X EN
Orchidaceae Epidendrum fusiforme (Lindl.) Rchb.f. X VU
Orchidaceae Epidendrum hombersleyi Summerh. X VU
Orchidaceae Epidendrum lanceolatum Bradford ex Griseb. X CR
Orchidaceae Maxillaria broadwayi (Cogn.) R.E.Schult. X CR
Orchidaceae Microchilus schultesianus (Garay) Ormerod X EN
Poaceae Neurolepis virgata (Griseb.) Pilg. X CR
Podocarpaceae Podocarpus trinitensis J.Buchholz & N.E.Gray X LC
Polygalaceae Polygala exserta S.F.Blake X CR
Polygalaceae Securidaca lophosoma (S.F.Blake) Cheesman X VU
Polygonaceae Coccoloba nigrescens Lindau X VU
Proteaceae Roupala tobagensis Sleumer X CR
Rubiaceae Psychotria rufidula Standl. X EN
Rubiaceae Rondeletia hispidula (Griseb.) K.Schum. X EN
Rubiaceae Rondeletia rohrii R.O.Williams & Cheesman ? ? DD
Urticaceae Pilea tobagensis Urb. X VU
Verbenaceae Aegiphila obovata Andrews X X NT
Xyridaceae Xyris grisebachii Malme X CR

References

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  1. ^ a b c d e f g h Van den Eynden, Veerle; Michael P. Oatham; Winston Johnson (2008). "How free access internet resources benefit biodiversity and conservation research: Trinidad and Tobago's endemic plants and their conservation status". Oryx. 42 (3): 400–07. doi:10.1017/S0030605308007321.
  2. ^ Acevedo-Rodríguez, Pedro (1996). Flora of St. John, U.S. Virgin Islands. Memoirs of The New York Botanical Garden. Vol. 78. Bronx, New York: The New York Botanical Garden. ISBN 0-89327-402-X.