Adansonia digitata

African baobabs are trees that often grow as solitary individuals, and are large and distinctive elements of savanna or scrubland vegetation. They grow to a height of . The trunk is typically very broad and fluted or cylindrical, often with a buttressed, spreading base. Trunks may reach a diameter of , The hollow core found in many tree species is the result of wood removal, such as decay of the oldest, internal part of the trunk. In baobabs, however, many of the largest and oldest of the trees have a hollow core that is the result of a fused circle of three to eight stems sprouting from roots. The fresh flowers have a sweet scent, but after about 24 hours, they start to turn brown and emit a carrion smell. Styles are white, growing through the staminal tube and projecting beyond it. They are usually bent at right-angles and topped with an irregular stigma. Pollen grains are spherical with spikes over the surface, typical of the Malvaceae family. Pollen grain diameter is around 50 microns. All Adansonia develop large rounded indehiscent fruit which can be up to long with a woody outer shell. African baobab fruit are quite variable in shape, from nearly round to cylindrical. The shell is thick. The seeds are hard and kidney-shaped with a 0.06-mm-thick coat. The water is absorbed into the vascular tissue of the tree, where it can be moved into the tree's parenchyma cells for long-term storage, or used. A large Baobab can store as much as 136,400 liters of water. During the dry season, the trees expel all of their leaves. During this period, the circumference of the trunk will shrink about 2–3 cm and the water content of the stem will drop by about 10%. Dropping leaves during the dry season is done to prevent water loss through transpiration out of the stomata, which would cause the water potentials in the vascular tissue to drop too low and pull water out of the vacuoles in the parenchyma cells. This would lead to the parenchyma cells, which make up the majority of the trunk and branches, to plasmolyse destroying the tree. Parenchyma are soft plant tissue cells that are commonly used for water storage in other drought tolerant species like cactus and succulents. The water fluxes from the vascular tissue into the parenchyma cells at the center of the tree with the help of actively transported ions. The ion flux into the cell will shift the concentration gradients, causing water to rush into the cells for long-term storage. Another reason why the water in the trunk can only be used as a buffer for long-term deficits is the distance between the vascular tissue and the parenchyma. The transportation of water from the vascular tissue into storage cells is a very slow process as it is a high-resistance path. The spongy material of the bark allows water to be absorbed deeper into the tissue, as there is rarely enough rain during the wet season to penetrate the litter layer of soil. The trees produce faint growth rings, but counting growth rings is not a reliable way to age baobabs because some years a tree will form multiple rings and some years none. Radiocarbon dating has provided data on a few individual A. digitata specimens. The Panke baobab in Zimbabwe was around 2,450 years old when it died in 2011, making it the oldest angiosperm ever documented, and two other trees—Dorslandboom in Namibia and Glencoe in South Africa—were estimated to be approximately 2,000 years old. Another specimen known as Grootboom was dated after it died and found to be at least 1,275 years old. Baobabs may be so long-lived in part due to their ability to periodically sprout new stems. ==Taxonomy==

The scientific name Adansonia refers to the French explorer and botanist, Michel Adanson (1727–1806), who wrote the first botanical description for the full species. A. digitata is the type species of the genus Adansonia and is the only species in the section Adansonia. Some populations of African baobab have significant genetic differences and it has been suggested that the taxon contains more than one species. For example, the shape of the fruit varies considerably from region to region. In Angola, the fruit are elongated, rather than round. ==Distribution and habitat==

The African baobab is associated with tropical savannas. It is native to mainland Africa, between the latitudes 16° N and 26° S. The northern limit of its distribution in Africa is associated with rainfall patterns; only on the Atlantic coast and in the Sudanian savanna does its occurrence venture naturally into the Sahel. On the Atlantic coast, this may be due to spreading after cultivation. Its occurrence is very limited in Central Africa, and it is found only in the very north of South Africa. In East Africa, the trees grow also in shrublands and on the coast. In Angola and Namibia, the baobabs grow in woodlands, and in coastal regions, in addition to savannas. The African Baobab is native to Mauritania, Senegal, Guinea, Sierra Leone, Mali, Burkina Faso, Ghana, Togo, Benin, Niger, Nigeria, northern Cameroon, Chad, Sudan, Congo Republic, DR Congo (formerly Zaire), Eritrea, Ethiopia, southern Somalia, Kenya, Tanzania, Zambia, Zimbabwe, Malawi, Mozambique, Angola, São Tomé, Príncipe, Annobon, South Africa (in Limpopo province, north of the Soutpansberg mountain range), Namibia, Botswana. Arab traders introduced it to northwestern Madagascar where baobab trees were often planted at the center of villages. ==Ecology==

All baobabs are deciduous, losing their leaves in the dry season, and remaining leafless for about eight months of the year. Pollination in the African baobab is achieved primarily by fruit bats, in West Africa mainly the straw-coloured fruit bat, Gambian epauletted fruit bat, and the Egyptian fruit bat. The flowers are also visited by galagos, and several kinds of insect. With their hard coat, baobab seeds can withstand drying and remain viable over long periods. The fruit is eaten by many species and the germination potential is improved when seeds have passed through the digestive tract of an animal, or have been subjected to fire. == Conservation ==

The baobab is a protected tree in South Africa, and yet is threatened by various mining and development activities. In the Sahel, the effects of drought, desertification and over-use of the fruit have been cited as causes for concern. , the African baobab is not yet classified by the IUCN Red List, although there is evidence that populations may be declining. Many of the largest and oldest African baobabs have died in recent years. == Uses ==

harvests baobab leaves for forage in the dry season. People have traditionally valued the trees as sources of food, water, health remedies or places of shelter. The baobab is a traditional food plant in Africa, but is little-known elsewhere. According to a modern field guide, the juice can help cure diarrhoea. The roots and fruit are edible. In Sudan, where the tree is called tebeldi (), people make tabaldi juice by soaking and dissolving the dry pulp of the fruit in water, locally known as gunguleiz. Water can also be extracted from some of the trunks. The seeds can be pounded into a flour Baobab leaves are sometimes used as forage for ruminants in dry season. The oilmeal, which is a byproduct of oil extraction, can also be used as animal feed. Whole fruit, or just the fruit pulp, can be stored for months under dry conditions. The fibre from the bark can be used to make cloth. In times of drought, elephants consume the juicy wood beneath the bark of the baobab. In 2009, the United States Food and Drug Administration granted generally recognised as safe status to baobab dried fruit pulp as a food ingredient. ==In culture==

Along the Zambezi, the tribes believed that baobabs were upright and too proud. The gods became angry and uprooted them and threw them back into the ground upside-down. Evil spirits now cause bad luck to anyone that picks up the sweet white flowers. More specifically, a lion will kill them. In Kafue National Park, one of the largest baobabs is known as "Kondanamwali" or the "tree that eats maidens". The tree fell in love with four beautiful maidens. When they reached puberty, they made the tree jealous by finding husbands. So, one night, during a thunderstorm, the tree opened its trunk and took the maidens inside. A rest house has been built in the branches of the tree. On stormy nights, the crying of the imprisoned maidens can still be heard. Prominent specimens A number of individual baobab trees attract sightseers due to their age, size, history, location or isolated occurrence. Cape Verde There is a large baobab tree in the town of Santa Maria on the island of Sal, Cape Verde islands. Botswana Around Gweta, Botswana, some have been declared national monuments. Green's Baobab, 27 km south of Gweta was inscribed by the 19th-century hunters and traders Frederick Thomas Green and Hendrik Matthys van Zyl besides other ruthless characters. Fred and Charles Green passed the baobab during an expedition to Lake Ngami and left the inscription "Green's Expedition 1858–1859". An earlier inscription by an unknown traveller reads "1771". About 11 km south of Green's Baobab is the turn-off to Chapman's Baobab, also known as Seven Sisters or Xaugam, i.e. "lion's tail" in Tsoa. It was once an enormous multi-stemmed tree, used by passing explorers, traders and travellers as a navigation beacon. It guided them as they navigated the extensive salt pan northwards, while a hollow in the trunk served as a letterbox. The explorer and hunter James Chapman left an engraving on a large root when he passed the tree with artist Thomas Baines in 1861, but Livingstone, Oswell, Moffat, and Selous also camped here. Livingstone supposedly carved a cross and his initials, and conveyed his 1853 sojourn in Missionary Travels, noting: "about two miles beyond [the immense saltpan Ntwetwe] we unyoked under a fine specimen of baobab, ... It consisted of 6 branches united into one trunk." It had a circumference of 25 m before its constituent trunks collapsed outward on 7 January 2016. Not all its trunks are confirmed dead however, one showing signs of life in 2019. Seven trees known as the Sleeping Sisters or Baines' Baobabs grow on a tiny islet in Kudiakam Pan, Botswana. They are named for Thomas Baines who painted them in May 1862, while en route to Victoria Falls. The fallen giant of Baines' day is still sprouting leaves (as of 2004), and a younger generation of trees are in evidence. The islet is accessible in winter when the pan is dry. Some large specimens have been transplanted to new sites, as was the one at Cresta Mowana lodge in Kasane. Ghana At Saakpuli (also Sakpele) in northern Ghana the site of a 19th-century slave transit camp is marked by a stand of large baobabs, to which slaves were chained. The chains were wrapped around their trunks or around the roots. Similarly, two trees at Salaga in central Ghana are reminders of the slave trade. One, located at the former slave market at the center of town, was replanted at the site of the original to which slaves were shackled. A second larger tree marks the slave cemetery, where bodies of dead slaves were dumped. India Inside the Golconda Fort in Hyderabad, India, is a baobab tree estimated to be 430 years old. It is the largest baobab outside of Africa. Madagascar , Madagascar The African baobab in Mahajanga, Madagascar, had a circumference of by 2013. It became the symbol of the city and was formerly a place for executions and important meetings. Mozambique The Lebombo Eco Trail tree is about tall with a diameter of almost . It was found to be about 1400 years old and made up of five stems with ages between 900 and 1400 years, fused in a ring leaving a large central cavity. The partially collapsed tree from which new stems have emerged is situated near the bank of the Saloum River at Kahone. It was formerly the venue for the gàmmu, an annual festival during which the kingdom's provincial rulers pledged their loyalty to the king. From 1593 to 1939, 49 kings of the Guélewars dynasty were inducted at this tree. It was beside the place where the Buur Saloum organised circumcision ceremonies, and in 1862, it became the scene of a battle. US Virgin Islands The Grove Place Baobab, listed as a Champion Tree, is believed to be the oldest (250–300 years) of some 100 baobabs on Saint Croix in the US Virgin Islands. It is seen as a living testament to centuries of African presence, as the seeds were likely introduced by an African slave who arrived at the former estate during the 18th century. According to the bronze memorial plaque, twelve women were rounded up during the 1878 Fireburn labor riot, and hanged beneath the tree. It has since been a rallying place for plantation laborers and unions. Zimbabwe Zimbabwe's Big Tree, near Victoria Falls, stands 25 metres tall and is visited by hundreds of thousands of tourists yearly. Radiocarbon dating has shown this one to be made up of several stems of various ages, with the oldest about 1150 years old. == Additional images ==

Slave Cemetry - Salaga.JPG|Baobab at the slave cemetery, Salaga. The white calico cloth indicates its spiritual significance. Baobab Adansonia digitata.jpg|In full leaf at Bagamoyo, Tanzania Adansonia digitata - baobabs.JPG|Without leaves in Tarangire National Park, Tanzania File:Starr 080305-3303 Adansonia digitata.jpg|Leaves File:Baobab - fruit pulp elements detail - Adansonia digitata.jpg|Elements of the fruit pulp (clockwise from top right): chunks, fibre, seeds, and pulp powder ==References==