Coleus is a former genus of flowering plants in the family Lamiaceae. In recent classifications, the genus is no longer recognized, the included species are instead placed in the genera Plectranthus and Solenostemon; because the type species, Coleus amboinicus is now placed in Plectranthus, Coleus is regarded as a synonym of Plectranthus. The term "coleus" is used as a common name for species placed in the genus Coleus that are cultivated as ornamental plants Coleus blumei, popular as a garden plant for its brightly colored foliage. Unlike the other plants, this plant is pointing the opposite direction of the sun. Coleus blumei = Coleus scutellarioides = Plectranthus scutellarioides Coleus amboinicus = Plectranthus amboinicus Coleus barbatus = Plectranthus barbatus Coleus caninus = Plectranthus caninus Coleus edulis = Plectranthus edulis Coleus esculentus = Plectranthus esculentus Coleus forskohlii = Plectranthus barbatus Coleus rotundifolius = Plectranthus rotundifolius Media related to Coleus at Wikimedia Commons
The tropics are the region of the Earth surrounding the Equator. They are delimited in latitude by The Tropic of Cancer in the Northern Hemisphere at 23°26′12.4″ N and the Tropic of Capricorn in the Southern Hemisphere at 23°26′12.4″ S. The tropics are referred to as the tropical zone and the torrid zone; the tropics include all the areas on the Earth where the Sun contacts a point directly overhead at least once during the solar year - thus the latitude of the tropics is equal to the angle of the Earth's axial tilt. The tropics are distinguished from the other climatic and biomatic regions of Earth, which are the middle latitudes and the polar regions on either side of the equatorial zone; the tropics contain 36 % of the Earth's landmass. As of 2014, the region is home to 40% of the world population, this figure is projected to reach 50% by the late 2030s. "Tropical" is sometimes used in a general sense for a tropical climate to mean warm to hot and moist year-round with the sense of lush vegetation.
Many tropical areas have a wet season. The wet season, rainy season or green season is the time of year, ranging from one or more months, when most of the average annual rainfall in a region falls. Areas with wet seasons are disseminated across portions of the subtropics. Under the Köppen climate classification, for tropical climates, a wet-season month is defined as a month where average precipitation is 60 millimetres or more. Tropical rainforests technically do not have dry or wet seasons, since their rainfall is distributed through the year; some areas with pronounced rainy seasons see a break in rainfall during mid-season when the intertropical convergence zone or monsoon trough moves poleward of their location during the middle of the warm season. When the wet season occurs during the warm season, or summer, precipitation falls during the late afternoon and early evening hours; the wet season is a time when air quality improves, freshwater quality improves and vegetation grows leading to crop yields late in the season.
Floods cause rivers to overflow their banks, some animals to retreat to higher ground. Soil nutrients erosion increases; the incidence of malaria increases in areas. Animals have survival strategies for the wetter regime; the previous dry season leads to food shortages into the wet season, as the crops have yet to mature. However, regions within the tropics may well not have a tropical climate. Under the Köppen climate classification, much of the area within the geographical tropics is classed not as "tropical" but as "dry", including the Sahara Desert, the Atacama Desert and Australian Outback. There are alpine tundra and snow-capped peaks, including Mauna Kea, Mount Kilimanjaro, the Andes as far south as the northernmost parts of Chile and Argentina. Tropical plants and animals are those species native to the tropics. Tropical ecosystems may consist of tropical rainforests, seasonal tropical forests, dry forests, spiny forests and other habitat types. There are significant areas of biodiversity, species endemism present in rainforests and seasonal forests.
Some examples of important biodiversity and high endemism ecosystems are El Yunque National Forest in Puerto Rico, Costa Rican and Nicaraguan rainforests, Amazon Rainforest territories of several South American countries, Madagascar dry deciduous forests, the Waterberg Biosphere of South Africa, eastern Madagascar rainforests. The soils of tropical forests are low in nutrient content, making them quite vulnerable to slash-and-burn deforestation techniques, which are sometimes an element of shifting cultivation agricultural systems. In biogeography, the tropics are divided into Neotropics. Together, they are sometimes referred to as the Pantropic; the Neotropical region should not be confused with the ecozone of the same name. "Tropicality" refers to the geographic imagery that many people outside the tropics have of that region. The idea of tropicality gained renewed interest in modern geographical discourse when French geographer Pierre Gourou published Les Pays Tropicaux, in the late 1940s.
Tropicality encompasses at least two contradictory imageries. One is that the tropics represent a Garden of a heaven on Earth; the latter view was discussed in Western literature—more so than the first. Evidence suggests that over time the more primitive view of the tropics in popular literature has been supplanted by more nuanced interpretations that reflect historical changes in values associated with tropical culture and ecology, although some primitive associations are persistent. Western scholars theorized about the reasons that tropical areas were deemed "inferior" to regions in the Northern Hemisphere. A popular explanation focused on the differences in climate—tropical regions have much warmer weather than northern regions; this theme led some scholars, including Gourou, to argue that warmer climates correlate to primitive indigenous populations lacking control over nature, compared to northern popul
Peter Thonning was a Danish physician and botanist. He was sent to Ghana by the Danish government to supervise the plantations of that colony, he lived there from 1799 to 1803, his herbarium was destroyed during the shelling of Copenhagen by the British in 1807. Only the duplicates and manuscripts in the possession of Heinrich Christian Friedrich Schumacher survived. Today, around 1,050 samples are preserved at the University of Copenhagen Botanical Garden; the genus Thonningia of parasitic plants was named after him by Martin Vahl. This botanist is denoted by the author abbreviation Thonn; when citing a botanical name
Plectranthus, with some 350 species, is a genus of warm-climate plants occurring in the Southern Hemisphere, in sub-Saharan Africa, Madagascar and the Indonesian archipelago down to Australia and some Pacific Islands. They are related to Solenostemon and are known as the spurflowers. Several species are grown as ornamental plants, as leaf vegetables, as root vegetables for their edible tubers, or as medicine. Plectranthus species are used as food plants by the larvae of some Lepidoptera species including the engrailed. Many plants called coleus belong to this genus, as Coleus is no longer recognized. Anisochilus carnosus Wall. Ex Benth. Isodon coetsa Kudô Isodon inflexus Kudô Isodon lophanthoides H. Hara Isodon rugosus Codd Isodon sculponeatus Kudô " Multilingual taxonomic information". University of Melbourne. EcoPort on P. rotundifolius PROTAbase on P. rotundifolius synonym for Solenostemon rotundifolius EcoPort on P. esculentus Lamiales Newsletter on P. esculentus Little-known African Tubers
Plectranthus amboinicus, once identified as Coleus amboinicus, is a semi-succulent perennial plant in the family Lamiaceae with a pungent oregano-like flavor and odor. It is native to Eastern Africa, it is cultivated and naturalized elsewhere in the tropics where it is used as a traditional medicine and ornamental plant. A Lamiaceae mint plant, Plectranthus amboinicus grows up to 1 m tall; the stem is fleshy, about 30–90 cm, either with long rigid hairs or densely covered with soft and erect hairs. Old stems are smooth. Leaves are 5–7 cm by 4–6 cm, undivided, egg/oval-shaped with a tapering tip; the margins are coarsely crenate to dentate-crenate except in the base. They are thickly studded with hairs, with the lower surface possessing the most numerous glandular hairs, giving a frosted appearance; the petiole is 2–4.5 cm. Flowers are on a short stem, pale purplish in dense, 10-20 flowered dense whorls at distant intervals in a long slender spike-like raceme. Rachis 10–20 cm, fleshy and pubescent.
The bracts are broadly ovate. The calyx is campanulate, 2–4 mm long and glandular, subequally 5-toothed, upper tooth broadly ovate-oblong, abruptly acute and lower teeth acute. Corolla blue and declinate, 8–12 mm long, tube 3–4 mm long. Trumpet-like widened. Filaments are fused below into a tube around the style; the seeds are smooth, pale-brown, roundish flattened, c. 0.7 by 0.5 mm. The aroma of the leaves can be described as a pungent combination of the aromas of oregano and turpentine; the taste of the leaves is described as being similar to the one of oregano, but with a sharp mint-like flavor. It is native to Southern and Eastern Africa, from South Africa and Swaziland to Angola and Mozambique and north to Kenya and Tanzania, where it grows in woodland or coastal bush, on rocky slopes and loamy or sandy flats at low elevations. From Southern Africa it would have been carried by Arabs and other traders to Arabia and Southeast Asia along the Indian Ocean maritime trade routes; the plant was brought to Europe, from Spain to the Americas, hence the name Spanish thyme.
In traditional medicine, Plectranthus amboinicus is thought to have medicinal properties, but there is no evidence from clinical research to support such claims. In basic research, the effects of the essential oil were tested with other plant essential oils for possible use as a mosquito repellant; the leaves are flavoured and used for stuffings of meat and poultry, beef and game. The herb is used as a substitute for oregano to mask the strong odors and flavors of fish and goat. Fresh leaves are used to scent hair, it is grown as an ornamental plant. The main chemical compounds found in the essential oil of Plectranthus amboinicus are carvacrol, thymol, α-humulene, undecanal, γ-terpinene, p-cymene, caryophyllene oxide, α-terpineol, β-selinene. Another analysis obtained thymol, carvacrol, 1,8-cineole, caryophyllene, terpinolene, α-pinene, β-pinene, methyl eugenol, β-phellandrene; the variations can be attributed to the methodology used in the extraction process, seasonal variations, soil type, climate and geographical variations of the plant.
Plectranthus amboinicus is a fast-growing plant grown in gardens and indoors in pots. Propagation is by stem cuttings, but it can be grown from seeds. In dry climates the herb grows in a well-drained, semi-shaded position, it is frost tender and grows well in subtropical and tropical locations, but will do well in cooler climates if grown in a pot and brought indoors, or moved to a warm, sheltered position in winter. In Hawaii and other humid tropical locations, the plant requires full sun. Cuban oregano Country borage French thyme Indian borage Indian mint Mexican mint Soup mint Spanish thyme Thick leaf thyme or broad leaf thyme A taxonomic revision of tribe Ocimeae Dumort. in continental South East Asia
Plectranthus rotundifolius or Solenostemon rotundifolius known as native or country potato in Africa and called Chinese potato in India is a perennial herbaceous plant of the mint family native to tropical Africa. It is cultivated for its edible tubers in West Africa, as well as more in parts of Asia India, Sri Lanka and Indonesia. P. Rotundifolius is related to the coleus plants cultivated as ornamentals and is classified as a member of the genus Solenostemon rather than Plectranthus, it was placed in the now-defunct genus Coleus, most of whose members have now been reassigned to the genus Solenostemon. The egg-shaped tubers of the native potato appear similar to the unrelated true potato, though they are smaller than modern commercial varieties, they are boiled, but may be roasted, baked, or fried. Their flavor is sweeter than P. esculentus. Native potato is overwhelmingly a subsistence crop, though flour milling is reported in Burkina FasoP. Rotundifolius is one of three Plectranthus species native to Africa grown for their edible tubers and using the same vernacular names.
The others, P. esculentus and P. edulis, native to southern Africa and Ethiopia have not spread beyond Africa
In the APG IV system for the classification of flowering plants, the name asterids denotes a clade. Common examples include the forget-me-nots, the common sunflower, morning glory and sweet potato, lavender, olive, honeysuckle, ash tree, snapdragon, psyllium, garden sage, table herbs such as mint and rosemary, rainforest trees such as Brazil nut. Most of the taxa belonging to this clade had been referred to the Asteridae in the Cronquist system and to the Sympetalae in earlier systems; the name asterids resembles the earlier botanical name but is intended to be the name of a clade rather than a formal ranked name, in the sense of the ICBN. The phylogenetic tree presented hereafter has been proposed by the APG IV project. Genetic analysis carried out after APG II maintains that the sister to all other asterids are the Cornales. A second order that split from the base of the asterids are the Ericales; the remaining orders cluster into two clades, the lamiids and the campanulids. The structure of both of these clades has changed in APG III.
In APG III system, the following clades were renamed: euasterids I → lamiids euasterids II → campanulids Asterids in Stevens, P. F.. Angiosperm Phylogeny Website. Version 7, May 2006