Recent from talks
Adansonia
Knowledge base stats:
Talk channels stats:
Members stats:
Adansonia
Adansonia is a genus of medium-to-large deciduous trees known as baobabs (/ˈbaʊbæb/ or /ˈbeɪoʊbæb/). The eight species of Adansonia are native to Africa, Australia, and Madagascar but have also been introduced to other regions of the world, including Barbados, where several of the baobabs there are suspected to have originated from Africa. Other baobabs have been introduced to Asia. A genomic and ecological analysis further suggests that the genus itself originated from Madagascar.
The generic name Adansonia honours Michel Adanson, the French naturalist and explorer who provided the first detailed botanical description and illustrations of Adansonia digitata. The baobab, however, is also known as the "upside down tree," a name attributable to the trees' overall appearance and historical myths. Baobabs are among the longest-lived of vascular plants and have large flowers that are reproductive for a maximum of 15 hours. The flowers open around dusk with sufficiently rapid movement that is detectable by the naked eye. The fruits are large, oval to round and berry-like, and hold kidney-shaped seeds in a dry, pulpy matrix.
In the early 21st century, baobabs in southern Africa began to die off rapidly and mysteriously—the cause is yet to be determined. Blight or pests are unlikely to have caused such rapid death, so some have speculated that the cause may have been mass dehydration.
Baobabs are long-lived deciduous, small to large trees from 5 to 30 m (20 to 100 ft) tall with broad trunks and compact crowns. Young trees usually have slender, tapering trunks, often with a swollen base. Mature trees have massive trunks that are bottle-shaped or cylindrical and tapered from bottom to top. The trunk is made of fibrous wood arranged in concentric rings, although rings are not always formed annually and so cannot be used to determine the age of individual trees. Tree diameter fluctuates with rainfall so it is thought that water may be stored in the trunk. Baobab trees have two types of shoots—long, green vegetative ones, and stout, woody reproductive ones. Branches can be massive and spread out horizontally from the trunk or are ascending.
Adansonia gregorii is generally the smallest of the baobabs, rarely getting to over 10 m (33 ft) tall and often with multiple trunks. Both A. rubrostipa and A. madagascariensis are small to large trees, from 5 to 20 m (16 to 66 ft) tall. The other baobabs grow from 25 to 30 m (80 to 100 ft) tall, with 2 to 3 m (7 to 10 ft) diameter trunks. A. digitata, however, often has massive single or multiple trunks of up to 10 m (33 ft) diameter.
Leaves are palmately compound in mature trees, but seedlings and regenerating shoots may have simple leaves. The transition to compound leaves comes with age and may be gradual. Leaves have 5–11 leaflets, with the largest ones in the middle and may be stalkless or with short petioles. Leaflets may have toothed or smooth edges, and may be hairless or have simple-to-clumped hairs. Baobabs have stipules at the base of the leaves, but the stipules are soon shed in most species. Baobabs are deciduous, shedding leaves during the dry season.
In most Adansonia species, the flowers are borne on short erect or spreading stalks in the axils of the leaves near the tips of reproductive shoots. Only A. digitata has flowers and fruits set on long, hanging stalks. There is usually only a single flower in an axil, but sometimes flowers occur in pairs. They are large, showy and strongly scented. They only open near dusk. Opening is rapid and movement of the flower parts is fast enough to be visible. Most Adansonia species are pollinated by bats.
Flowers may remain attached to the trees for several days, but the reproductive phase is very short, with pollen shed during the first night and stigmas shriveled by the morning. The flower is made up of an outer 5-lobed calyx, and an inner ring of petals set around a fused tube of stamens. The outer lobes of the calyx are usually green (brown in A. grandidieri) and in bud are joined almost to the tip. As the flower opens, the calyx lobes split apart and become coiled or bent back (reflexed) at the base of the flower. The inner surface of the lobes are silky-hairy and cream, pink, or red. Sometimes the lobes do not separate cleanly, distorting the shape of the flower as they bend back. The calyx lobes remain fused at the base, leaving a feature (calyx tube) that has nectar-producing tissue and that is cup-shaped, flat or tubular; the form of the calyx tube varies with species. The flowers have a central tube (staminal tube) made up of fused stalks of stamens (filaments), with unfused filaments above. A densely hairy ovary is enclosed in the staminal tube, and a long style tipped with a stigma emerges from the filaments. Petals are set near the base of the staminal tube and are variable in shape and colour. The flowers, when fresh, may be white, cream, bright yellow or dark red, but fade quickly, often turning reddish when dried.
Hub AI
Adansonia AI simulator
(@Adansonia_simulator)
Adansonia
Adansonia is a genus of medium-to-large deciduous trees known as baobabs (/ˈbaʊbæb/ or /ˈbeɪoʊbæb/). The eight species of Adansonia are native to Africa, Australia, and Madagascar but have also been introduced to other regions of the world, including Barbados, where several of the baobabs there are suspected to have originated from Africa. Other baobabs have been introduced to Asia. A genomic and ecological analysis further suggests that the genus itself originated from Madagascar.
The generic name Adansonia honours Michel Adanson, the French naturalist and explorer who provided the first detailed botanical description and illustrations of Adansonia digitata. The baobab, however, is also known as the "upside down tree," a name attributable to the trees' overall appearance and historical myths. Baobabs are among the longest-lived of vascular plants and have large flowers that are reproductive for a maximum of 15 hours. The flowers open around dusk with sufficiently rapid movement that is detectable by the naked eye. The fruits are large, oval to round and berry-like, and hold kidney-shaped seeds in a dry, pulpy matrix.
In the early 21st century, baobabs in southern Africa began to die off rapidly and mysteriously—the cause is yet to be determined. Blight or pests are unlikely to have caused such rapid death, so some have speculated that the cause may have been mass dehydration.
Baobabs are long-lived deciduous, small to large trees from 5 to 30 m (20 to 100 ft) tall with broad trunks and compact crowns. Young trees usually have slender, tapering trunks, often with a swollen base. Mature trees have massive trunks that are bottle-shaped or cylindrical and tapered from bottom to top. The trunk is made of fibrous wood arranged in concentric rings, although rings are not always formed annually and so cannot be used to determine the age of individual trees. Tree diameter fluctuates with rainfall so it is thought that water may be stored in the trunk. Baobab trees have two types of shoots—long, green vegetative ones, and stout, woody reproductive ones. Branches can be massive and spread out horizontally from the trunk or are ascending.
Adansonia gregorii is generally the smallest of the baobabs, rarely getting to over 10 m (33 ft) tall and often with multiple trunks. Both A. rubrostipa and A. madagascariensis are small to large trees, from 5 to 20 m (16 to 66 ft) tall. The other baobabs grow from 25 to 30 m (80 to 100 ft) tall, with 2 to 3 m (7 to 10 ft) diameter trunks. A. digitata, however, often has massive single or multiple trunks of up to 10 m (33 ft) diameter.
Leaves are palmately compound in mature trees, but seedlings and regenerating shoots may have simple leaves. The transition to compound leaves comes with age and may be gradual. Leaves have 5–11 leaflets, with the largest ones in the middle and may be stalkless or with short petioles. Leaflets may have toothed or smooth edges, and may be hairless or have simple-to-clumped hairs. Baobabs have stipules at the base of the leaves, but the stipules are soon shed in most species. Baobabs are deciduous, shedding leaves during the dry season.
In most Adansonia species, the flowers are borne on short erect or spreading stalks in the axils of the leaves near the tips of reproductive shoots. Only A. digitata has flowers and fruits set on long, hanging stalks. There is usually only a single flower in an axil, but sometimes flowers occur in pairs. They are large, showy and strongly scented. They only open near dusk. Opening is rapid and movement of the flower parts is fast enough to be visible. Most Adansonia species are pollinated by bats.
Flowers may remain attached to the trees for several days, but the reproductive phase is very short, with pollen shed during the first night and stigmas shriveled by the morning. The flower is made up of an outer 5-lobed calyx, and an inner ring of petals set around a fused tube of stamens. The outer lobes of the calyx are usually green (brown in A. grandidieri) and in bud are joined almost to the tip. As the flower opens, the calyx lobes split apart and become coiled or bent back (reflexed) at the base of the flower. The inner surface of the lobes are silky-hairy and cream, pink, or red. Sometimes the lobes do not separate cleanly, distorting the shape of the flower as they bend back. The calyx lobes remain fused at the base, leaving a feature (calyx tube) that has nectar-producing tissue and that is cup-shaped, flat or tubular; the form of the calyx tube varies with species. The flowers have a central tube (staminal tube) made up of fused stalks of stamens (filaments), with unfused filaments above. A densely hairy ovary is enclosed in the staminal tube, and a long style tipped with a stigma emerges from the filaments. Petals are set near the base of the staminal tube and are variable in shape and colour. The flowers, when fresh, may be white, cream, bright yellow or dark red, but fade quickly, often turning reddish when dried.
Recent media