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Flora Of Saint Helena
The flora of Saint 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. In phytogeography, it is in the phytochorion St. Helena and Ascension Region of the African Subkingdom, in the Paleotropical Kingdom. Endemic and introduced flora The endemic plants of Saint Helena include many notable Cabbage Tree or, "insular arborescent Asteraceae", members of the Asteraceae, daisy 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 dwarf ebony (''Trochetiopsis ebenus''). These are unrelated to the Sequoia sempervirens, redwood trees of California or to the Diospyros, ebony trees of commerce, being instead in the Mallow family (Malvaceae). Vegetation Today there are three major vegetation zones: the tree-fern thicket of the highest parts of the central ridge; t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cabbage Trees
Cabbage, comprising several cultivars of ''Brassica oleracea'', is a leafy green, red (purple), or white (pale green) biennial plant grown as an Annual plant, annual vegetable crop for its dense-leaved heads. It is descended from the wild cabbage (Brassica oleracea, ''B. oleracea'' var. ''oleracea''), and belongs to the "cole crops" or brassicas, meaning it is closely related to broccoli and cauliflower (var. ''botrytis''); Brussels sprouts (var. ''gemmifera''); and Savoy cabbage (var. ''sabauda''). A cabbage generally weighs between . Smooth-leafed, firm-headed green cabbages are the most common, with smooth-leafed purple cabbages and crinkle-leafed savoy cabbages of both colours being rarer. Under conditions of long sunny days, such as those found at high northern latitudes in summer, cabbages can grow quite large. , the heaviest cabbage was . Cabbage heads are generally picked during the first year of the plant's Biological life cycle, life cycle, but plants intended fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinction
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and recover. As a species' potential Range (biology), range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxon, Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the Fossil, fossil record) after a period of apparent absence. Over five billion species are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryotes globally, possibly many times more if microorganisms are included. Notable extinct animal species include Dinosaur, non-avian dinosaurs, Machairodontinae, saber-toothed cats, and mammoths. Through evolution, species arise through the process of specia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commidendrum Spurium
''Commidendrum spurium'', the false gumwood, is a species of flowering plant in the family Asteraceae. It is found only in Saint Helena. Its natural habitats are subtropical or tropical moist lowland forests, rocky areas, and rocky shores. It is threatened by habitat loss Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease .... References spurium Critically endangered plants Flora of Saint Helena Taxonomy articles created by Polbot Plants described in 1836 {{Astereae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commidendrum Rugosum
''Commidendrum rugosum'', known as scrubwood, is a species of flowering plant in the family Asteraceae. Description The plant is endemic to the island of Saint Helena, off the coast of Africa. Its natural habitats are subtropical or tropical dry shrubland, rocky areas, and rocky shores. It is an IUCN Red List Vulnerable species, threatened by habitat loss Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease .... References rugosum Flora of Saint Helena Vulnerable flora of Africa Taxonomy articles created by Polbot Plants described in 1836 {{Astereae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commidendrum Rotundifolium
''Commidendrum rotundifolium'', the bastard gumwood, is a species of tree endemic to the island of Saint Helena. It was thought to be extinct, but one last tree was discovered in Horse Pasture in 1982. This tree, long believed to be the last, was destroyed in 1986 by a gale. However seedlings were grown from this tree before it perished. The last of these to survive in cultivation was damaged by gales in 2008 and the survival of the species was in doubt. In December 2009, Lourens Malan, a horticulturist working for the island's conservation department under the Critical Species Recovery Project, discovered a wild tree growing on a cliff. A local team of botanists, conservationists and volunteers commenced an intensive programme of hand pollination and seed collection of the remaining cultivated tree, while protecting it from insects that may cross-pollinate with nearby false gumwoods. Successful fertilisation will occur only if any grains of pollen happen to have mutation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commidendrum Robustum
''Commidendrum robustum'', the Saint Helena gumwood, is a species of tree endemic to the island of Saint Helena in the British Overseas Territory of Saint Helena, Ascension and Tristan da Cunha. Though it is now comparatively rare, it was once one of the most abundant trees of mid-elevations of Saint Helena in the South Atlantic Ocean. A small tree reaching a maximum of in height, it was cut extensively for fuel in the early years of settlement of the island by the English East India Company. It is one of several species in the endemic genus '' Commidendrum''. ''Commidendrum robustum'' is closely related to the Melanodendron integrifolium, Black cabbage tree, which also inhabits Saint Helena. The two species most likely evolved from a common ancestor. Today, the closest relatives are South African, in the small shrub genus ''Felicia'' Cass. and ''Amellus'' L. Description Gumwood trees reach in height when fully grown with an umbrella shaped canopy. However, when they first sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chenopodium Helenense
''Chenopodium'' is a genus of numerous species of perennial or annual herbaceous flowering plants known as the goosefoot, which occur almost anywhere in the world. It is placed in the family Amaranthaceae in the APG II system; older classification systems, notably the widely used Cronquist system, separate it and its relatives as Chenopodiaceae, but this leaves the rest of the Amaranthaceae polyphyletic. However, among the Amaranthaceae, the genus ''Chenopodium'' is the namesake member of the subfamily Chenopodioideae. Description The species of ''Chenopodium'' (s.str., description according to Fuentes et al. 2012) are annual or perennial herbs, shrubs or small trees. They generally rely on alkaline soil. They are nonaromatic, but sometimes fetid (foul-smelling). The young stems and leaves are often densely covered by vesicular globose hairs, thus looking farinose. Characteristically, these trichomes persist, collapsing later and becoming cup-shaped. The branched stems gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acalypha Rubrinervis
''Acalypha rubrinervis'' (string tree or stringwood) is an extinct plant in the spurge family (Euphorbiaceae), from the island of Saint Helena in the South Atlantic Ocean. It was called string tree on account of the thin pendulous inflorescences which resembled red strings. Disturbance following human settlement on the island destroyed its habitat and it was last seen in the 19th century. It is thus one of a number of island plants to have been driven to extinction by human activity (see List of extinct plants). The genus to which it belongs, '' Acalypha'', is a large one and includes island endemics as well as weeds and ornamentals. ''A. rubrinervis'' was a shrub or thicket growing on the central ridge of St Helena above 600 m elevation. ''Acalypha rubrinervis'' is a shrub or small tree, 1–2 m. Branches with warty leaf-scars. Leaves ovate to broadly triangular-ovate, entire to somewhat wavy-toothed, with 3 veins from the base of the leaf blade 5-7 x 3–5 cm, leaf stalk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dicotyledons
The dicotyledons, also known as dicots (or, more rarely, dicotyls), are one of the two groups into which all the flowering plants (angiosperms) were formerly divided. The name refers to one of the typical characteristics of the group: namely, that the seed has two embryonic leaves or cotyledons. There are around 200,000 species within this group. The other group of flowering plants were called monocotyledons (or monocots), typically each having one cotyledon. Historically, these two groups formed the two divisions of the flowering plants. Largely from the 1990s onwards, molecular phylogenetic research confirmed what had already been suspected: that dicotyledons are not a group made up of all the descendants of a common ancestor (i.e., they are not a monophyletic group). Rather, a number of lineages, such as the magnoliids and groups now collectively known as the basal angiosperms, diverged earlier than the monocots did; in other words, monocots evolved from within the di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eragrostis Saxatilis
''Eragrostis'' is a large and widespread genus of plants in the grass family, found in many countries on all inhabited continents and many islands. ''Eragrostis'' is commonly known as lovegrass or canegrass. The name of the genus is derived from the Greek words ἔρως (''érōs''), meaning "love", and ἄγρωστις (''ágrōstis''), meaning "grass". Lovegrass is commonly used as livestock fodder. The seeds appear to be of high nutritional value for some animals, but they are also very tiny and collecting them for human food is cumbersome and hence uncommon. A notable exception is teff ('' E. tef''), which is used to make traditional breads on the Horn of Africa, such as Ethiopian '' injera'' and Somalian '' laxoox''. It is a crop of commercial importance. '' E. clelandii'' and '' E. tremula'' are recorded as famine foods in Australia and Chad Chad, officially the Republic of Chad, is a landlocked country at the crossroads of North Africa, North and Central Afri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carex Praealta
''Carex'' is a vast genus of over 2,000 species of grass-like plants in the family Cyperaceae, commonly known as sedges (or seg, in older books). Other members of the family Cyperaceae are also called sedges, however those of genus ''Carex'' may be called true sedges, and it is the most species-rich genus in the family. The study of ''Carex'' is known as caricology. Description All species of ''Carex'' are perennial, although some species, such as '' C. bebbii'' and '' C. viridula'' can fruit in their first year of growth, and may not survive longer. They typically have rhizomes, stolons or short rootstocks, but some species grow in tufts (caespitose). The culm – the flower-bearing stalk – is unbranched and usually erect. It is usually distinctly triangular in section. The leaves of ''Carex'' comprise a blade, which extends away from the stalk, and a sheath, which encloses part of the stalk. The blade is normally long and flat, but may be folded, inrolled, channell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carex Dianae
''Carex dianae'' (common name, Diana's Peak Grass) is a tussock-forming species of perennial sedge in the family Cyperaceae. It is native to St Helena Saint Helena (, ) is one of the three constituent parts of Saint Helena, Ascension and Tristan da Cunha, a remote British overseas territory. Saint Helena is a volcanic and tropical island, located in the South Atlantic Ocean, some 1,874 km .... Description ''Carex dianae'' is a tussock-forming, grasslike, perennial plant with small flowers which are grouped into spikes and grows in impoverished, rocky terrain. See also * List of ''Carex'' species References dianae Plants described in 1855 Taxa named by Ernst Gottlieb von Steudel Flora of Saint Helena {{Carex-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
