Dorstenia | |
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Pseudanthium of Dorstenia hildebrandtii | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Rosales |
Family: | Moraceae |
Tribe: | Dorstenieae |
Genus: | Dorstenia Plum. ex L. (1753) |
Species [1] | |
122; see text | |
Synonyms [1] | |
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Dorstenia is a genus within the mulberry family, Moraceae. Depending on the author, there are said to be 100 to 170 species within this genus, second only in number to the genus Ficus within Moraceae. Plants of the World Online currently accepts 122 species. [1] Dorstenia species are mainly known for their unusual inflorescences and growth habits. Dorstenia is named in honor of the German physician and botanist Theodor Dorsten (1492–1552). [2] The type species is Dorstenia contrajerva .
Dorstenia is unique in the family Moraceae because of the extremely diverse growth habits and forms of its species. While the majority of Moraceae are woody perennials, Dorstenia species are predominantly herbaceous, succulent, or suffrutescent perennials. Only 10% exhibit the typical woody habit of the Moraceae. [3]
The spectrum of the genus Dorstenia ranges from small annuals to perennial herbaceous plants with and without rhizomes or tubers, geophytes, lithophytes, epiphytes, woody shrubs and succulents (stem or leaf succulents). Their juice is mostly milky white, rarely yellow or colorless. The hairs that are found on most species are at least partially hook-shaped.
The leaves mostly are arranged in spirals and rosettes, and rarely as two-rowed leaves. The leaf blades may be shield-, hand- or foot-shaped, whole, incised, lobed or feathered. Usually the leaf edges are perforated or notched. The ever-present stipulae are also variable in shape. Usually they are leathery, sometimes large, leaf-like and durable or sometimes small, awl-shaped and quickly falling off. [3]
The most striking characteristic of Dorstenia is their reproductive structure, called pseudanthium (Greek for "false flower") or in Moraceae hypanthium, which is composed of clusters of tiny unisexual flowers on a disc- or cup-shaped receptacle that are often adorned with bracts of various sizes and shapes. The pseudanthiums can be planar, convex, concave, round, oval, square, lobed, twig, star, boot, or tongue-shaped. Their color varies from green to yellowish and reddish to violet and brown. Beneath the pseudanthium, there are usually bracts, scattered or in rows, sometimes carrying appendages. Sometimes the bracts are absent and only their remaining tooth-shaped, awl-like, spatula-shaped or band-shaped appendages are recognizable.
The globular, tapered, or warty flowers are unisexual. The female flowers within the receptacle mature first. The male flowers are either scattered between the female flowers or are concentrated on the outer edge of the receptacle or are separated by a flower-free zone at the outer edge. They are stalked and carry one to four (usually two to three) free or almost free tepals and one to four (usually two to three) stamens. The sunken female flowers carry tubular tepals and a free fruit node with one or two, then mostly unequal scars. Like most members of the Moraceae, Dorstenia species have drupe-like fruits that are embedded in the receptacle. However, a special feature of Dorstenia drupes is that they explode to release and scatter the seeds by way of a centrifugal mechanism. The stone seeds are usually small with a minuscule endosperm. [3]
Dorstenia is part of the tribe Dorstenieae of the family Moraceae, and all three levels of classification are monophyletic from chloroplast and nuclear DNA phylogenies, with morphological characters that also support. [4] The family Moraceae is a part of the monophyletic order Rosales, and within this order Moraceae is most closely related to the plant families Ulmaceae, Cannabaceae, and Urticaceae. [5]
Fossils of Ficus and Morus fruits have been found on the African continent, and are used to approximate the origin of the family Moraceae to a maximum of 135 million years ago. In a recent study using fossil fruits, Bayesian molecular dating, and maximum likelihood, researchers attempted to reconstruct the ancestral history of Dorstenia with ITS (internal transcribed spacer) sequences from ribosomal DNA of 35 Dorstenia species and seven out-group species from the different tribes within the Moraceae. The goal was to resolve a long-standing issue regarding Dorstenia; whether this genus diverged and radiated prior to the split of Africa and South America about 105 mya, and members of this genus are on separate continents by vicariance, or if this genus diverged post-split and Dorstenia became established in the Neotropics by seed dispersal. [6]
This study produced a phylogeny indicating an initial Old World divergence around 112.3 mya, divergence and radiance of New World Dorstenia at 67.2 and 30.3 mya respectively, and an Old World group nested within the New World that radiated around 13.6 mya. The results of this phylogeny do not reveal whether vicariance or seed dispersal explains the biogeography; however, due to the small endosperm that is typical of Dorstenia seeds, it is unlikely that seed dispersal by animals is the reason for the New World and reemerged Old World species. The pattern seen does suggest several hypotheses regarding how the New World lineage came about as well as how three Old World Dorstenia species are nested in the New World clade. It is theorized that the New World lineage crossed over via Asia and then Beringia, established populations all throughout the North and South Americas, and when climate conditions changed (and North America was no longer tropical or subtropical), that the North American populations died out, leaving only those in South America. This idea also theoretically allows for Old World species nested within the New World lineage, with Dorstenia populations established in America returning to Africa via Beringia while climatic conditions were still favorable. For this hypothesis to receive more credence, fossil Dorstenia plants in North America would be needed. [6]
The species are fairly equally distributed between the Afrotropics and Neotropics. Only one species grows east of Arabia, in the tropical forests of Southern India and Sri Lanka.
South American species such as Dorstenia contrajerva and Dorstenia brasiliensis [7] are a source of the herbal preparation contrayerva that has been used as a tonic and febrifuge, and as an antidote in South American folk medicine. [7] [8] In North America powder made from the rootstocks and leaves of Dorstenia contrajerva is mixed with tobacco for improving the taste of cigarettes. [9] In Oman the tubers of Dorstenia foetida are cooked and eaten. [10] Dorstenia barteri is used in West African folk medicine. Scientific research has shown that it contains numerous flavonoid compounds that have anti-microbial, anti-reverse transcriptase, and anti-inflammatory effects. [11] [12]
In the past many species were described that are now considered synonyms. This is due to the great variability of many Dorstenia species. New species are still discovered, such as Dorstenia luamensis a hanging lithophyte from Congo, first described in 2014. [13] The following list includes species accepted by Plants of the World Online. [1]
The Cucurbitaceae, also called cucurbits or the gourd family, are a plant family consisting of about 965 species in 101 genera. Those most important to humans are the following:
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.
The Moraceae—often called the mulberry family or fig family—are a family of flowering plants comprising about 38 genera and over 1100 species. Most are widespread in tropical and subtropical regions, less so in temperate climates; however, their distribution is cosmopolitan overall. The only synapomorphy within the Moraceae is presence of laticifers and milky sap in all parenchymatous tissues, but generally useful field characters include two carpels sometimes with one reduced, compound inconspicuous flowers, and compound fruits. The family includes well-known plants such as the fig, banyan, breadfruit, jackfruit, mulberry, and Osage orange. The 'flowers' of Moraceae are often pseudanthia.
Celtis is a genus of about 60–70 species of deciduous trees, commonly known as hackberries or nettle trees, in the hemp family Cannabaceae. It has a cosmopolitan distribution.
The Portulacaceae are a family of flowering plants, comprising 115 species in a single genus Portulaca. Formerly some 20 genera with about 500 species, were placed there, but it is now restricted to encompass only one genus, the other genera being placed elsewhere. The family has been recognised by most taxonomists, and is also known as the purslane family. It has a cosmopolitan distribution, with the highest diversity in semiarid regions of the Southern Hemisphere in Africa, Australia, and South America, but with a few species also extending north into Arctic regions. The family is very similar to the Caryophyllaceae, differing in the calyx, which has only two sepals.
Orobanchaceae, the broomrapes, is a family of mostly parasitic plants of the order Lamiales, with about 90 genera and more than 2000 species. Many of these genera were formerly included in the family Scrophulariaceae sensu lato. With its new circumscription, Orobanchaceae forms a distinct, monophyletic family. From a phylogenetic perspective, it is defined as the largest crown clade containing Orobanche major and relatives, but neither Paulownia tomentosa nor Phryma leptostachya nor Mazus japonicus.
Trophis is a genus in the plant family Moraceae which includes five species native to the tropical Americas, ranging from Mexico through Central America and the Caribbean to Peru and northern Brazil. It is dioecious, with male and female flowers borne on separate plants.
Brosimum is a genus of plants in the family Moraceae, native to tropical regions of the Americas.
Naucleopsis is a genus of flowering plants in the mulberry family, Moraceae. It includes 25 species native to the tropical Americas, ranging from Honduras to Bolivia and southeastern Brazil.
Antiaris toxicaria is a tree in the mulberry and fig family, Moraceae. It is the only species currently recognized in the genus Antiaris. The genus Antiaris was at one time considered to consist of several species, but is now regarded as just one variable species which can be further divided into five subspecies. One significant difference within the species is that the size of the fruit decreases as one travels from Africa to Polynesia. Antiaris has a remarkably wide distribution in tropical regions, occurring in Australia, tropical Asia, tropical Africa, Indonesia, the Philippines, Tonga, and various other tropical islands. Its seeds are spread by various birds and bats, and it is not clear how many of the populations are essentially invasive. The species is of interest as a source of wood, bark cloth, and pharmacological or toxic substances.
Moreae is a tribe within the plant family Moraceae. It includes 6–10 genera and 70–80 species, including Morus, the genus that includes the mulberries, and Maclura, the genus that includes the Osage orange.
Dorstenia contrajerva is a plant species in the family Moraceae. It is native to Northern South America and Central America, and is cultivated elsewhere. The species name "contrajerva" is the Latinized form of the plant's Spanish name, "contrahierba", a name for plants used for treating poisoning and venomous bites and stings, and for which its rootstocks are used in folk medicine. It is the type species of the Dorstenia genus and was first described by Carl Linnaeus in 1753.
Dorstenia flagellifera is a plant species in the family Moraceae which is native to Haiti.
Dorstenia nummularia is a plant species in the family Moraceae which is native to Cuba.
Ficus vasta, is a fig plant found in Ethiopia and Yemen. The tree is a species of sycamore-fig.
Maquira is a genus of trees in the family Moraceae, native to South America.