The Neuradaceae are a family of flowering plant, comprising three genera — Grielum and Neuradopsis — totalling ten known species. These genera were placed in order Rosales, in one case in family Rosaceae, but they are now recognised as belonging to order Malvales; the family needs further research
Adansonia is a genus of deciduous trees known as baobabs. They are found in arid regions of Madagascar, mainland Africa and Australia; the generic name honours Michel Adanson, the French naturalist and explorer who described Adansonia digitata. In the early 21st century, baobabs in southern Africa began to die off from a cause yet to be determined. Scientists believe it is unlikely that disease or pests were able to kill many trees so while some speculated that the die-off was a result of dehydration from global warming. Baobabs have trunk diameters of 7 to 11 m; the Glencoe baobab, a specimen of A. digitata in Limpopo Province, South Africa, was considered to be the largest living individual, with a maximum circumference of 47 m and a diameter of about 15.9 m. The tree has since split into two parts, so the widest individual trunk may now be that of the Sunland baobab, or Platland tree in South Africa; the diameter of this tree at ground level is 9.3 m and its circumference at breast height is 34 m.
Adansonia trees produce faint growth rings annually, but they are not reliable for aging specimens, because they are difficult to count and may fade away as the wood ages. Radiocarbon dating has provided data on a few individuals of A. digitata. The Panke baobab in Zimbabwe was some 2,450 years old when it died in 2011, making it the oldest angiosperm documented, two other trees — Dorslandboom in Namibia and Glencoe in South Africa — were estimated to be 2,000 years old. Another specimen known as Grootboom was found to be at least 1275 years old. Greenhouse gases, climate change, global warming appear to be factors reducing baobab longevity. Of the nine species accepted as of April 2018, six are native to Madagascar, two are native to mainland Africa and the Arabian Peninsula, one is native to Australia. One of the mainland African species occurs on Madagascar, but it is not a native of that island, it was introduced in ancient times during the colonial era to the Caribbean. It is present in the island nation of Cape Verde.
The ninth species was described in 2012, is found in upland populations of southern and eastern Africa. The African and Australian baobabs are identical despite having separated more than 100 million years ago by oceanic dispersal. Species include:Adansonia digitata L. – African baobab, dead-rat-tree, monkey-bread-tree Adansonia grandidieri Baill. – Grandidier's baobab, giant baobab Adansonia gregorii F. Muell. – boab, Australian baobab, cream-of-tartar-tree, gouty-stem Adansonia kilima Pettigrew, et al. – montane African baobab Adansonia madagascariensis Baill. – Madagascar baobab Adansonia perrieri Capuron – Perrier's baobab Adansonia rubrostipa Jum. & H. Perrier – fony baobab Adansonia suarezensis H. Perrier – Suarez baobab Adansonia za Baill. – za baobab The Malagasy species are important components of the Madagascar dry deciduous forests. Within that biome, Adansonia madagascariensis and A. rubrostipa occur in the Anjajavy Forest, sometimes growing out of the tsingy limestone itself. A. digitata has been called "a defining icon of African bushland".
Baobabs store water in the trunk to endure harsh drought conditions. All occur in seasonally arid areas, are deciduous, shedding their leaves during the dry season. Across Africa, the oldest and largest baobabs began to die in the early 21st century from a combination of drought and rising temperatures; the trees appear to become parched become dehydrated and unable to support their massive trunks. Baobabs are important as nest sites for birds, in particular the mottled spinetail and four species of weaver. Leaves may be eaten as a leaf vegetable; the fruit has a velvety shell and is about the size of a coconut, weighing about 1.5 kilograms, but is not as globular. The fresh fruit is said to taste like sorbet, it has an acidic, citrus flavor. It is a good source of vitamin C, potassium and phosphorus; the dried fruit powder of Adansonia digitata, baobab powder, contains about 12% water and modest levels of various nutrients, including carbohydrates, calcium, potassium and phytosterols, with low levels of protein and fats.
Vitamin C content, described as variable in different samples, was in a range of 74 to 163 milligrams per 100 grams of dried powder. In Angola, the dry fruit is boiled and the broth is used for juices or as the base for a type of ice cream known as gelado de múcua. In Zimbabwe, the fruit is used in traditional food preparations which include "eating the fruit fresh or crushed crumbly pulp to stir into porridge and drinks". In the European Union, prior to commercial approval, baobab fruit powder was not available for use as a food ingredient, as legislation from 1997 dictated that foods not consumed in the EU would have to be formally approved first. In 2008, baobab dried fruit pulp was authorized in the EU as a safe food ingredient, in the year was granted GRAS status in the United States; the seeds of some species are a source of vegetable oil, The fruit pulp and seeds of A. grandidieri and A. za are eaten fresh. In Tanzania, the dry pulp of A. digitata is added to sugarcane to aid fermentation in brewing.
Some baobab species are sources of fiber
Chocolate is a sweet, brown food preparation of roasted and ground cacao seeds. It is made in the form of a liquid, paste, or in a block, or used as a flavoring ingredient in other foods; the earliest evidence of use traces to the Olmecs, with evidence of chocolate beverages dating to 1900 BC. The majority of Mesoamerican people made chocolate beverages, including Aztecs. Indeed, the word "chocolate" is derived from the Classical Nahuatl word chocolātl; the seeds of the cacao tree have an intense bitter taste and must be fermented to develop the flavor. After fermentation, the beans are dried and roasted; the shell is removed to produce cacao nibs, which are ground to cocoa mass, unadulterated chocolate in rough form. Once the cocoa mass is liquefied by heating, it is called chocolate liquor; the liquor may be cooled and processed into its two components: cocoa solids and cocoa butter. Baking chocolate called bitter chocolate, contains cocoa solids and cocoa butter in varying proportions, without any added sugar.
Powdered baking cocoa, which contains more fiber than it contains cocoa butter, can be processed with alkali to produce dutch cocoa. Much of the chocolate consumed today is in the form of sweet chocolate, a combination of cocoa solids, cocoa butter or added vegetable oils, sugar. Milk chocolate is sweet chocolate that additionally contains condensed milk. White chocolate contains cocoa butter and milk, but no cocoa solids. Chocolate is one of the most popular food types and flavors in the world, many foodstuffs involving chocolate exist desserts, including cakes, mousse, chocolate brownies, chocolate chip cookies. Many candies are filled with or coated with sweetened chocolate, bars of solid chocolate and candy bars coated in chocolate are eaten as snacks. Gifts of chocolate molded into different shapes are traditional on certain Western holidays, including Christmas, Valentine's Day, Hanukkah. Chocolate is used in cold and hot beverages, such as chocolate milk and hot chocolate, in some alcoholic drinks, such as creme de cacao.
Although cocoa originated in the Americas, West African countries Côte d'Ivoire and Ghana, are the leading producers of cocoa in the 21st century, accounting for some 60% of the world cocoa supply. With some two million children involved in the farming of cocoa in West Africa, child slavery and trafficking were major concerns in 2018. However, international attempts to improve conditions for children were failing because of persistent poverty, absence of schools, increasing world cocoa demand, more intensive farming of cocoa, continued exploitation of child labor. Chocolate has been prepared as a drink for nearly all of its history. For example, one vessel found at an Olmec archaeological site on the Gulf Coast of Veracruz, dates chocolate's preparation by pre-Olmec peoples as early as 1750 BC. On the Pacific coast of Chiapas, Mexico, a Mokaya archaeological site provides evidence of cacao beverages dating earlier, to 1900 BC; the residues and the kind of vessel in which they were found indicate the initial use of cacao was not as a beverage, but the white pulp around the cacao beans was used as a source of fermentable sugars for an alcoholic drink.
An early Classic-period Mayan tomb from the site in Rio Azul had vessels with the Maya glyph for cacao on them with residue of a chocolate drink, suggests the Maya were drinking chocolate around 400 AD. Documents in Maya hieroglyphs stated chocolate was used for ceremonial purposes, in addition to everyday life; the Maya grew cacao trees in their backyards, used the cacao seeds the trees produced to make a frothy, bitter drink. By the 15th century, the Aztecs gained control of a large part of Mesoamerica and adopted cacao into their culture, they associated chocolate with Quetzalcoatl, according to one legend, was cast away by the other gods for sharing chocolate with humans, identified its extrication from the pod with the removal of the human heart in sacrifice. In contrast to the Maya, who liked their chocolate warm, the Aztecs drank it cold, seasoning it with a broad variety of additives, including the petals of the Cymbopetalum penduliflorum tree, chile pepper, allspice and honey; the Aztecs were not able to grow cacao themselves, as their home in the Mexican highlands was unsuitable for it, so chocolate was a luxury imported into the empire.
Those who lived in areas ruled by the Aztecs were required to offer cacao seeds in payment of the tax they deemed "tribute". Cocoa beans were used as currency. For example, the Aztecs used a system in which one turkey cost 100 cacao beans and one fresh avocado was worth three beans; the Maya and Aztecs associated cacao with human sacrifice, chocolate drinks with sacrificial human blood. The Spanish royal chronicler Gonzalo Fernández de Oviedo described a chocolate drink he had seen in Nicaragua in 1528, mixed with achiote: "because those people are fond of drinking human blood, to make this beverage seem like blood, they add a little achiote, so that it turns red.... and part of that foam is left on the lips and around the mouth, when it is red for having achiote, it seems a horrific thing, because it seems like blood itself." Until the 16th century, no European had heard of the popular drink from the Central American peoples. Christopher Columbus and his son Ferdinand encountered the cacao bean on Columbus's fourth mission to the Americas on 15 August 1502, when he and his crew seized a large native canoe that proved to contain cacao beans among other goods for trade.
Spanish conquistador Hernán Cortés may have been the first European to encounter it, as the frothy drink was part of t
A sepal is a part of the flower of angiosperms. Green, sepals function as protection for the flower in bud, as support for the petals when in bloom; the term sepalum was coined by Noël Martin Joseph de Necker in 1790, derived from the Greek σκεπη, a covering. Collectively the sepals are called the outermost whorl of parts that form a flower; the word calyx was adopted from the Latin calyx, not to be confused with a cup or goblet. Calyx derived from the Greek κάλυξ, a bud, a calyx, a husk or wrapping, while calix derived from the Greek κυλιξ, a cup or goblet, the words have been used interchangeably in botanical Latin. After flowering, most plants have no more use for the calyx which becomes vestigial; some plants retain a thorny calyx, either dried or live, as protection for seeds. Examples include species of Acaena, some of the Solanaceae, the water caltrop, Trapa natans. In some species the calyx not only persists after flowering, but instead of withering, begins to grow until it forms a bladder-like enclosure around the fruit.
This is an effective protection against some kinds of birds and insects, for example in Hibiscus trionum and the Cape gooseberry. Morphologically, both sepals and petals are modified leaves; the calyx and the corolla are the outer sterile whorls of the flower, which together form what is known as the perianth. The term tepal is applied when the parts of the perianth are difficult to distinguish, e.g. the petals and sepals share the same color, or the petals are absent and the sepals are colorful. When the undifferentiated tepals resemble petals, they are referred to as "petaloid", as in petaloid monocots, orders of monocots with brightly coloured tepals. Since they include Liliales, an alternative name is lilioid monocots. Examples of plants in which the term tepal is appropriate include genera such as Tulipa. In contrast, genera such as Rosa and Phaseolus have well-distinguished petals; the number of sepals in a flower is its merosity. Flower merosity is indicative of a plant's classification.
The merosity of a eudicot flower is four or five. The merosity of a monocot or palaeodicot flower is a multiple of three; the development and form of the sepals vary among flowering plants. They may be fused together; the sepals are much reduced, appearing somewhat awn-like, or as scales, teeth, or ridges. Most such structures protrude until the fruit is mature and falls off. Examples of flowers with much reduced perianths are found among the grasses. In some flowers, the sepals are fused towards the base. In other flowers a hypanthium includes the bases of sepals and the attachment points of the stamens. Plant morphology
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
Theobroma cacao called the cacao tree and the cocoa tree, is a small evergreen tree in the family Malvaceae, native to the deep tropical regions of the Americas. Its seeds, cocoa beans, are used to make cocoa solids, cocoa butter and chocolate. Leaves are alternate, unlobed, 10–40 cm long and 5–20 cm broad; the flowers are produced in clusters directly on older branches. The flowers are small, 1–2 cm diameter, with pink calyx; the floral formula, used to represent the structure of a flower using numbers, is ✶ K5 C5 A G. While many of the world's flowers are pollinated by bees or butterflies/moths, cacao flowers are pollinated by tiny flies, Forcipomyia midges in the subfamily Forcipomyiinae. Using the natural pollinator Forcipomyia midges for Theobroma cacao was shown to have more fruit production than using artificial pollinators; the fruit, called a cacao pod, is ovoid, 15–30 cm long and 8–10 cm wide, ripening yellow to orange, weighs about 500 g when ripe. The pod contains 20 to 60 seeds called "beans", embedded in a white pulp.
The seeds are the main ingredient of chocolate, while the pulp is used in some countries to prepare refreshing juice, smoothies and nata. Discarded until practices changed in the 21st century, the fermented pulp may be distilled into an alcoholic beverage; each seed contains a significant amount of fat as cocoa butter. The fruit's active constituent is a compound similar to caffeine. Cacao belongs to the genus Theobroma classified under the subfamily Byttnerioideae of the mallow family Malvaceae. Cacao is one of 17 species of Theobroma. In 2008, researchers proposed a new classification based upon morphological and genomic criteria: 10 groups have been named according to their geographic origin or the traditional cultivar name; these groups are: Amelonado, Nacional, Curaray, Cacao guiana, Marañon, Purús. The generic name is derived from the Greek for "food of the gods"; the specific name cacao is the Hispanization of the name of the plant in indigenous Mesoamerican languages. The cacao was known as kakaw in K'iche' and Classic Maya.
T. cacao is distributed from southeastern Mexico to the Amazon basin. There were two hypotheses about its domestication. More recent studies of patterns of DNA diversity, suggest that this is not the case. One study classified them into 10 distinct genetic clusters; this study identified areas, for example around Iquitos in modern Peru and Ecuador, where representatives of several genetic clusters originated more than 5000 years ago, leading to development of the variety, Nacional cocoa bean. This result suggests that this is where T. cacao was domesticated for the pulp that surrounds the beans, eaten as a snack and fermented into a mildly alcoholic beverage. Using the DNA sequences and comparing them with data derived from climate models and the known conditions suitable for cacao, one study refined the view of domestication, linking the area of greatest cacao genetic diversity to a bean-shaped area that encompasses Ecuador, the border between Brazil and Peru and the southern part of the Colombian-Brazilian border.
Climate models indicate that at the peak of the last ice age 21,000 years ago, when habitat suitable for cacao was at its most reduced, this area was still suitable, so provided a refugium for the species. Cacao trees grow well as understory plants in humid forest ecosystems; this is true of abandoned cultivated trees, making it difficult to distinguish wild trees from those whose parents may have been cultivated. Cultivation and cultural elaboration of cacao were early and extensive in Mesoamerica. Ceramic vessels with residues from the preparation of cacao beverages have been found at archaeological sites dating back to the Early Formative period. For example, one such vessel found at an Olmec archaeological site on the Gulf Coast of Veracruz, Mexico dates cacao's preparation by pre-Olmec peoples as early as 1750 BC. On the Pacific coast of Chiapas, Mexico, a Mokaya archaeological site provides evidence of cacao beverages dating earlier, to 1900 BC; the initial domestication was related to the making of a fermented, thus alcoholic beverage.
In 2018, researchers who analysed the genome of cultivated cacao trees concluded that the domesticated cacao trees all originated from a single domestication event that occurred about 3,600 years ago somewhere in Central America. Several mixtures of cacao are described in ancient texts, for ceremonial or medicinal, as well as culinary, purposes; some mixtures included maize, chili and honey. Archaeological evidence for use of cacao, while sparse, has come from the recovery of whole cacao beans at Uaxactun and from the preservation of wood fragments of the cacao tree at Belize sites including Cuello and Pulltrouser Swamp. In addition, analysis of residues from ceramic vessels has found traces of theobromine and caffeine in early formative vessels from Puerto Escondido, Honduras and in middle formative vessels from Colha, Belize using similar techniques to those used to extract chocolate residues from four classic period (around 400
Antoine Laurent de Jussieu
Antoine Laurent de Jussieu was a French botanist, notable as the first to publish a natural classification of flowering plants. His classification was based on an extended unpublished work by his uncle, the botanist Bernard de Jussieu. Jussieu was born in Lyon, he went to Paris to study medicine, graduating in 1770. He was professor of botany at the Jardin des Plantes from 1770 to 1826, his son Adrien-Henri became a botanist. In his study of flowering plants, Genera plantarum, Jussieu adopted a methodology based on the use of multiple characters to define groups, an idea derived from naturalist Michel Adanson; this was a significant improvement over the "artificial" system of Linnaeus, whose most popular work classified plants into classes and orders based on the number of stamens and pistils. Jussieu did keep Linnaeus' binomial nomenclature, resulting in a work, far-reaching in its impact. Morton's 1981 History of botanical science counts 76 of Jussieu's families conserved in the ICBN, versus just 11 for Linnaeus, for instance.
Writing of the natural system, Sydney Howard Vines remarked "The glory of this crowning achievement belongs to Jussieu: he was the capable man who appeared at the psychological moment, it is the men that so appear who have made, will continue to make, all the great generalisations of science." In 1788, he was elected a foreign member of the Royal Swedish Academy of Sciences. He was a member of Les Neuf Sœurs; the system of suprageneric nomenclature in botany is dated to 4 Aug 1789 with the publication of the Genera Plantarum. De Jussieu system