Syconium (pl.: syconia) is the type of fruit borne by figs (genus Ficus ), formed by an enlarged, fleshy, hollow receptacle with multiple ovaries on the inside surface. [1] [2] In essence, it is really a fleshy stem with a number of flowers, so it is considered both a multiple and accessory fruit.
The term syconium comes from the Ancient Greek word συκον (sykon), meaning "fig". [2]
The syconium is an urn-shaped receptacle which contains between 50 and 7000 (depending on the species) highly simplified uniovulate flowers or florets on its inner surface. It is closed off from most organisms by the ostiole, fringed by scale-like bracts.
Syconia can be monoecious or functionally dioecious: the former contain female flowers with variable style length and few male flowers, and produce seeds and pollen. The latter have male and female forms in different plants: seed figs contain female flowers with long styles and produce seeds; gall figs contain female flowers with short styles and male flowers and produce pollen.
Once pollinated by a fig wasp, the individual florets inside the syconium develop into achenes or drupes, in which the seeds are enclosed by a layer of endocarp. From this perspective, the fig is an enclosure with tens to thousands of fruits within it. [3]
Formation of the syconium begins with the initial growth of bracts, which curve to form a receptacle. When the outer bracts meet, they form the ostiole by interlock. Syconia may also develop lateral, basal, or peduncular bracts. There is a relationship between the shape of the ostiole and the morphology of the pollinating wasp. [4]
The tight ostiolar enclosure at the syconium's apex makes it highly pollinator-specific. When receptive to pollen, the ostiole slightly loosens, allowing the highly specialized wasps to enter through it. The wasps lose their wings in the process, and once inside they pollinate female flowers as they lay their eggs in some ovules, which then form galls. The wasps then die and larvae develop in the galls, while seeds develop in the pollinated flowers. 4–6 weeks after egg laying, the wingless males emerge, mate with the females still in their galls, and cut a tunnel out of the syconium. As the females emerge, they collect pollen from male flowers, which ripen later. After the wasps emerge, chemical changes in the fig follow as the fig develops into 'fruit'. [5] [6]
The syconium is thought to have first evolved 83 million years ago in the Cretaceous [7] within an entomophilic clade within Moraceae that includes tribe Castilleae and genus Ficus, as the bracts protecting the inflorescence tightened to form the ostiole. This greatly increased the pollinator specificity of the plant and initiated a long and complex history of coevolution between figs and their pollinating wasps (agaonids).
Ficus is a genus of about 850 species of woody trees, shrubs, vines, epiphytes and hemiepiphytes in the family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few species extending into the semi-warm temperate zone. The common fig (F. carica) is a temperate species native to southwest Asia and the Mediterranean region, which has been widely cultivated from ancient times for its fruit, also referred to as figs. The fruit of most other species are also edible though they are usually of only local economic importance or eaten as bushfood. However, they are extremely important food resources for wildlife. Figs are also of considerable cultural importance throughout the tropics, both as objects of worship and for their many practical uses.
Fig wasps are wasps of the superfamily Chalcidoidea which spend their larval stage inside figs. Some are pollinators but others simply feed off the plant. The non-pollinators belong to several groups within the superfamily Chalcidoidea, while the pollinators are in the family Agaonidae. While pollinating fig wasps are gall-makers, the remaining types either make their own galls or usurp the galls of other fig wasps; reports of their being parasitoids are considered dubious.
Ficus macrophylla, commonly known as the Moreton Bay fig or Australian banyan, is a large evergreen banyan tree of the Mulberry Family (Moraceae) native to eastern Australia, from the Wide Bay–Burnett region in the north to the Illawarra in New South Wales, as well as Lord Howe Island where the subspecies F. m. columnaris is a banyan form covering 2.5 acres or more of ground. Its common name is derived from Moreton Bay in Queensland, Australia. It is best known for its imposing buttress roots.
Ficus rubiginosa, the rusty fig or Port Jackson fig, is a species of flowering plant native to eastern Australia in the genus Ficus. Beginning as a seedling that grows on other plants (hemiepiphyte) or rocks (lithophyte), F. rubiginosa matures into a tree 30 m (100 ft) high and nearly as wide with a yellow-brown buttressed trunk. The leaves are oval and glossy green and measure from 4 to 19.3 cm long and 1.25 to 13.2 cm wide.
The family Agaonidae is a group of pollinating fig wasps. They spend their larval stage inside the fruits of figs. The pollinating wasps are the mutualistic partners of the fig trees. Extinct forms from the Eocene and Miocene are nearly identical to modern forms, suggesting that the niche has been stable over geologic time.
Ficus citrifolia, also known as the shortleaf fig, giant bearded fig, Jagüey, wild banyantree and Wimba tree, is a species of banyan native to southern Florida, the Caribbean, Mexico, Central America, and northern South America south to Paraguay. It is distinguished from the closely related Florida strangler fig mainly by the finer veining in the leaves.
Ficus pumila var. awkeotsang, also known as the jelly fig, aiyu, or ai-yu, is a variety of Ficus pumila, and a member of the fig family Moraceae, native to Taiwan. The plant is known for its use in making aiyu jelly.
Ficus aurea, commonly known as the Florida strangler fig, golden fig, or higuerón, is a tree in the family Moraceae that is native to the U.S. state of Florida, the northern and western Caribbean, southern Mexico and Central America south to Panama. The specific epithet aurea was applied by English botanist Thomas Nuttall who described the species in 1846.
Pegoscapus is a genus of fig wasp native to the Americas. They range from Florida and Mexico in the north to Argentina in the south. Fig wasps have an obligate mutualism with the fig species they pollinate. Pegoscapus pollinates species in section Americana of the subgenus Urostigma.
Ficus maxima is a fig tree which is native to Mexico, Central America, the Caribbean and South America south to Paraguay. Figs belong to the family Moraceae. The specific epithet maxima was coined by Scottish botanist Philip Miller in 1768; Miller's name was applied to this species in the Flora of Jamaica, but it was later determined that Miller's description was actually of the species now known as Ficus aurea. To avoid confusion, Cornelis Berg proposed that the name should be conserved for this species. Berg's proposal was accepted in 2005.
Ficus insipida is a common tropical tree in the fig genus of the family Moraceae growing in forest habitats along rivers. It ranges from Mexico to northern South America.
Ficus watkinsiana, commonly known as strangler fig, Watkins' fig, nipple fig or the green-leaved Moreton Bay fig is a hemiepiphytic fig that is endemic to Australia. The species exists in three populations—one in northeast Queensland and the others in southeast Queensland and northeast New South Wales. It also has been introduced to Kauai island (Hawaiʻi).
Ficus obliqua, commonly known as the small-leaved fig, is a tree in the family Moraceae, native to eastern Australia, New Guinea, eastern Indonesia to Sulawesi and islands in the southwestern Pacific Ocean. Previously known for many years as Ficus eugenioides, it is a banyan of the genus Ficus, which contains around 750 species worldwide in warm climates, including the edible fig. Beginning life as a seedling, which grows on other plants (epiphyte) or on rocks (lithophyte), F. obliqua can grow to 60 m (200 ft) high and nearly as wide with a pale grey buttressed trunk, and glossy green leaves.
Ficus hispida, also known as the opposite leaf Fig, is a small tree in the family Moraceae, with a distribution ranging from India and southern China southwards to northern Australia. It is morphologically gynodioecious, but functionally dioecious. Male trees are hermaphrodites with both staminate flowers that produce pollen and pistillate flowers that produce almost no seeds but can form galls containing pollinator wasp larvae. Female trees have pistillate flowers that do produce seeds but are inhospitable to pollinator wasp larvae.
Blastophaga psenes is a wasp species in the genus Blastophaga. It pollinates the common fig Ficus carica and the closely related Ficus palmata. Without a colony or nest, these wasps breed in figs, and the adults live for only a few days or weeks. They locate the fig they wish to pollinate through olfactory senses.
Ficus auriculata is a type of fig tree, native to subtropical and tropical mainland Asia. It is noted for its big and round leaves and edible fruit.
Ceratosolen is an Old World wasp genus in the family Agaonidae. They are pollinators of the monoecious fig subsections Sycomorus and Sycocarpus, and the section Neomorphe, all belonging to the subgenus Sycomorus. The genus is native to the Palearctic, Afrotropical, Indomalayan and Australasian realms.
Ficus exasperata, also called the sandpaper tree, forest sandpaper fig, white fig, or sandpaper leaf tree, is a deciduous, and dioecious species of plant in the mulberry family Moraceae, native to tropical Africa and southern Asia.
The genus Ficus is composed of 800 species of vines, shrubs, and trees, defined by their syconiums, the fruit-like vessels that either hold female flowers or pollen on the inside. In addition to being cultivated by humans for thousands of years, Ficus is also known for their reproductive mutualism with the fig wasp.
Ficus amplissima, also known as the Indian bat tree, Indian bat fig, Pimpri, Pipri (Piparee), Pipali or Bilibasari mara is a tree species of flowering plants that belongs to Moraceae, the fig or mulberry family. It is native to Central and southern Peninsular India, Sri Lanka and Maldives, having a significant distribution throughout Western Ghats of India. It is most commonly planted to provide shade in coffee plantations due to its dense and wide foliage. The ripened figs attract many birds, especially during the spring.
