The flora of St Helena, an isolated island in the South Atlantic Ocean is exceptional in its high level of endemism and the severe threats facing the survival of the flora. ^[1]

Endemic and introduced flora

The endemic plants of St Helena include many notable "insular arborescent Asteraceae", that is, members of the sunflower family which have evolved a shrubby or tree-like habit on islands. Other notable endemics include the closely related St Helena redwood (Trochetiopsis erythroxylon) and St Helena ebony (Trochetiopsis ebenus). These are unrelated to the redwood trees of California or to the ebony trees of commerce, being instead in the Cocoa family (Sterculiaceae). Genera many, see list The aster or sunflower family (Family Asteraceae or, alternatively Family Compositae) is a taxon of dicotyledonous flowering plants. ... Binomial name Helianthus annuus L. The sunflower (Helianthus annuus) is an annual plant in the family Asteraceae, with a large flower head (inflorescence). ... Binomial name Sequoia sempervirens (D. Don) Endl. ... Species 450-500; see text Diospyros is a genus (including what used to be Maba) of about 450-500 species of deciduous and evergreen trees. ... Genera Abelmoschus - Okra Abutilon - Abutilon Adansonia – Baobab Alcea - Hollyhock Althaea - Marsh mallow Bombax – Silk-cotton tree Callirhoe - Poppy mallow Ceiba – Kapok Chiranthodendron – Mexican Hand Tree Cola - Kola nut Corchorus - Jute Durio – Durian Fremontodendron – Flannelbush Gaya – Gaya Gossypium - Cotton plant Hibiscus - Hibiscus Hoheria &#8211...

Vegetation

Today there are three major vegetation zones: the tree-fern thicket of the highest parts of the central ridge; the pastures of middle elevations and the barren, eroded "crown wastes" of lower elevations. Of these only the tree-fern thicket is a natural vegetation type. The middle elevations were formerly covered with native woodland of gumwoods (Commidendrum) and other trees, now largely destroyed. The barren "Crown wastes" were formerly covered with native scrub, of which a major component was probably St Helena ebony (Trochetiopsis ebenus and Trochetiopsis melanoxylon).

Human impact and conservation

The destruction of the native vegetation began soon after the discovery of the island by the Portuguese in 1502, with the introduction of goats. As there were no native herbivorous mammals, the flora was unadapted to such threats. Later with the establishment of permanent settlement on the island by the English East India Company in 1659, many introduced plants became established which created new vegetation types. Furthermore the native trees were subject to catastrophic cutting for such purposes as housebuilding and to fuel stills for the distillation of arrack. As a result of this legacy many endemic plant species are extinct or critically endangered. The British East India Company, popularly known as John Company, was founded by a Royal Charter of Queen Elizabeth I on December 31, 1600. ... Arrack refers to the strong spirits distilled mainly in South East Asia from fermented fruits, grains, sugarcane, or the sap of coconuts or other palm trees. ...

List of endemic vascular plants of St Helena

Monocotyledons Divisions Non-seed-bearing plants Equisetophyta Lycopodiophyta Psilotophyta Pteridophyta Superdivision Spermatophyta Pinophyta Cycadophyta Ginkgophyta Gnetophyta Magnoliophyta The vascular plants are those plants that have specialized cells for conducting water and sap within their tissues, including the flowering plants, conifers and other gymnosperms, but not mosses, algae, and the like (nonvascular... Orders Base Monocots: Acorus Alismatales Asparagales Dioscoreales Liliales Pandanales Family Petrosaviaceae Commelinids: Arecales Commelinales Poales Zingiberales Family Dasypogonaceae Monocotyledons or monocots are a group of flowering plants usually ranked as a class and once called the Monocotyledoneae. ...

Bulbostylis lichtensteiniana (Kunth) C.B. Clarke, Bulbostylis neglecta (Hemsl.) C.B. Clarke, Carex dianae Steud., Carex praealta Boott, Eragrostis saxatilis Hemsl.

Dicotyledons Orders see text Dicotyledons or dicots are flowering plants whose seed contains two embryonic leaves or cotyledons. ...

Acalypha rubrinervis Cronk, Chenopodium helenense Aellen, Commidendrum robustum (Roxb.) DC. spp. robustum, Commidendrum robustum (Roxb.) DC. ssp. gummiferum (Roxb.) Cronk, Commidendrum rotundifolium (Roxb.) DC., Commidendrum rugosum (Aiton) DC., Commidendrum spurium (G. Forst.) DC., Euphorbia heleniana Thell. & Stapf, Frankenia portulacifolia (Roxb.) Spreng., Heliotropium pannifolium Burch. ex Hemsl., Hydrodea cryptantha (Hook.f.) N.E.Br., Hypertelis acida (Hook.f.) K. Müll., Lachanodes arborea (Roxb.) B. Nord., Melanodendron integrifolium (Roxb.) DC., Mellissia begonifolia (Roxb.) Hook.f., Nesiota elliptica (Roxb.) Hook.f., Nesohedyotis arborea (Roxb.) Bremek., Osteospermum sanctae-helenae Norl., Pelargonium cotyledonis (L.) L'Hér., Petrobium arboreum (J.R. & G. Forst.) R. Br., Phylica polifolia (Vahl) Pillans, Pladaroxylon leucadendron ( G. Forst.) Hook.f., Plantago robusta Roxb., Sium bracteatum (Roxb.) Cronk, Sium burchellii (Hook.f.) Hemsl., Suaeda fruticosa Forssk. ex J.F. Gmel., Trimeris scaevolifolia (Roxb.) Mabb., Trochetiopsis ebenus Cronk, Trochetiopsis erythroxylon (G. Forst.) Marais, Trochetiopsis melanoxylon (Sol. ex Sims) Marais, Trochetiopsis x benjaminii Cronk, Wahlenbergia angustifolia (Roxb.) A.DC., Wahlenbergia burchellii A.DC. in DC., Wahlenbergia linifolia (Roxb.) A.DC., Wahlenbergia roxburghii A.DC.,

Pteridophytes (Ferns and fern-allies) Classes Marattiopsida Osmundopsida Gleicheniopsida Pteridopsida A fern, or pteridophyte, is any one of a group of some twenty thousand species of plants classified in the Division Pteridophyta, formerly known as Filicophyta. ...

Asplenium compressum Sw., Asplenium platybasis Kunze ex Mett., Ceterach haughtoni (Hook.) Cronk, Dicksonia arborescens L'Hér., Diplazium filamentosum (Roxb.) Cronk, Dryopteris cognata (C. Presl) Kuntze, Dryopteris napoleonis (Bory) Kuntze, Elaphoglossum dimorphum (Hook. & Grev.) Moore, Elaphoglossum nervosum (Bory) H.Christ, Grammitis ebenina (Maxon) Tardieu, Hymenophyllum capillaceum Roxb., Lycopodium axillare Roxb., Microstaphyla furcata (L.f.) Fée, Ophioglossum polyphyllum A. Braun, Pseudophegopteris dianae (Hook.) Holttum, Pteris paleacea Roxb.

See also

• List of extinct plants. Includes several from St Helena

Achyranthes mangarevica Acacia prismifolia Acacia volubilis Acalypha rubra Acianthus ledwardii Acmadenia baileyensis Acmadenia candida Adenia natalensis Amperea xiphoclada Amphibromus whitei Anacyclus alboranensis Angraecum carpophorum Anthurium leuconeurum Araucaria mirabilis Argentipallium spiceri Argyreia soutteri Argyrolobium splendens Argyroxiphium virescens Armeria arcuata Artemisia insipida Asclepias bicuspis Aspalathus variegata Astiria rosea Astragalus kentrophyta Badula ovalifolia...

External links

• Plant talk article: saving the remarkable flora of St Helena
• A potted history of the flora of St Helena and its conservation

Footnotes and references