Cucurbitales
Encyclopedia
The Cucurbitales are an order of flowering plant
s, included in the rosid group of dicotyledon
s. This order mostly belongs to tropical areas, with limited presence in subtropic and temperate regions. The order includes shrubs and trees, together with many herbs and climbers. One of major characteristics of the Cucurbitales is the presence of unisexual flowers, mostly pentacyclic, with thick pointed petals (whenever present) (Matthews and Endress, 2004). The pollination is usually performed by insects, but wind pollination
is also present (in Coriariaceae and Datiscaceae
).
The order consists of roughly 2600 species in eight families. The largest families are Begoniaceae
(begonia family) with 1400 species and Cucurbitaceae
(gourd family) with 825 species. The large families of Cucurbitales include several economically important plants. Specifically, the Cucurbitaceae (gourd family} are responsible for some food species, such as squash
, pumpkin
(both from Cucurbita
), melon including watermelon
(Citrullus vulgaris), and cucumber
(Cucumis
). The Begoniaceae are known for their horticultural species, of which there are over 130.
trees. Cucurbitales form an important component of tropical forests from low to montane forests with greater representation in terms of number of species. Although not known with certainty the total number of species in the family, conservative estimates indicate approximately 2.600 species worldwide, distributed in 109 genera. Compared to other plant families, the taxonomy of the family is poorly understood due to their great diversity, difficulty in identifying and reduced taxonomic work done on it.
The order Cucurbitales in the eurosid I clade comprises almost 2600 species in 109 or 110 genera in 8 families, tropical and temperate, of very different sizes, morphology, and ecology. It is a case of divergent evolution
. In contrast, there is convergent evolution
with other groups not related due to ecological or physical drivers toward a similar solution, including analogous structures.
Some botanical species are trees having similar foliage to the Lauraceae
due to convergent evolution.
The patterns of speciation in the Cucurbitales is diversified in a high number of species. They have a pantropical distribution with centers of diversity in Africa South America and Southeast Asia. They most likely originated in West Gondwana
and are 67–107 million years old, so the oldest split could relate to the break-up of Gondwana in the middle Eocene to late Oligocene, 45–24 million years ago, and reached their current distribution by multiple intercontinental dispersal events. One factor was product of aridification, others groups responded to favourable climatic periods and expanded across the available habitat, occur as opportunistic species across wide distribution other groups diverged in long time isolated areas.
The order Cucurbitales is composed by the families: Anisophylleaceae
, Begoniaceae
, Coriariaceae, Corynocarpaceae, Cucurbitaceae
, Tetramelaceae
and Datiscaceae
. Some of the synapomorphies of the order are: leaves in spiral, secondary veins palmated, calyx or perianth valvate, elevated stomatal calyx/perianth with separate styles. The two whorls similar in texture.
Tetrameles nudiflora
is a tree of immense proportions of height and width, Tetramelaceae
, Anisophylleaceae
and Corynocarpaceae are tall canopy trees in temperate and tropical forest. The genus Dendrosicyos
with the only species cucumber tree, is adapted to arid semi desert island of Socotra
. Deciduous perennial cucurbitales lose all of their leaves
for part of the year depending on variations in rain
fall. The leaf loss coincides with the dry season
in tropical, subtropical and arid regions. In temperate
or polar climate
s the dry season is due to the inability of the plant to absorb water available by to be in the form of ice.
Half of the species know are in the great diverse Begonia group of Begoniaceae with 2 genera, and 1500 species. Because of the lack of worldwide knowledge about the order in general, very little is known about the order diversity. The knowledge of this order to national level, is that to be expected in countries with limited economic means with the vast majority of species indeterminate or even poorly determined. Therefore an increase in the study of order, at national level, is of utmost importance for the progress of the systematics of the order in general. The increase in the number of species is expected for the genera, bringing an expected considerable increase in the total number of species of the family. Before DNA-molecular classifications, the species placed now in eight families of cucurbitales order, was assigned to orders as diverse as Ranunculales
, Malpighiales
, Violales
, and Rafflesiales
. Early molecular studies revealed several surprises, such as the non-monophyly of the traditional Datiscaceae
, including Tetrameles and Octomeles
, but the exact relationships among the families remained unclear.
, the first four families (including Begoniaceae
, Cucurbitaceae
, and Datiscaceae
), were placed in the order Violales
, within the Dilleniidae, with the Tetramelaceae subsumed within the Datiscaceae. The other families were distributed throughout various orders. The present classification is due to APG II (2003)
.
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
s, included in the rosid group of dicotyledon
Dicotyledon
The dicotyledons, also known as dicots, are a group of flowering plants whose seed typically has two embryonic leaves or cotyledons. There are around 199,350 species within this group...
s. This order mostly belongs to tropical areas, with limited presence in subtropic and temperate regions. The order includes shrubs and trees, together with many herbs and climbers. One of major characteristics of the Cucurbitales is the presence of unisexual flowers, mostly pentacyclic, with thick pointed petals (whenever present) (Matthews and Endress, 2004). The pollination is usually performed by insects, but wind pollination
Anemophily
Anemophily or wind pollination is a form of pollination whereby pollen is distributed by wind. Anemophilous plants may be either gymnosperms or angiosperms ....
is also present (in Coriariaceae and Datiscaceae
Datiscaceae
Datiscaceae are a family of Dicotyledonous plants, containing two species of the genus Datisca. Two other genera, Octomeles and Tetrameles are now classified in the Tetramelaceae family....
).
The order consists of roughly 2600 species in eight families. The largest families are Begoniaceae
Begoniaceae
Begoniaceae is a family of flowering plants with about 1400 species occurring in the subtropics and tropics of both the New World and Old World. All but one of the species are in the genus Begonia. The only other genus in the family, Hillebrandia, is endemic to the Hawaiian Islands and has a single...
(begonia family) with 1400 species and Cucurbitaceae
Cucurbitaceae
The plant family Cucurbitaceae consists of various squashes, melons, and gourds, including crops such as cucumber, pumpkins, luffas, and watermelons...
(gourd family) with 825 species. The large families of Cucurbitales include several economically important plants. Specifically, the Cucurbitaceae (gourd family} are responsible for some food species, such as squash
Squash (fruit)
Squashes generally refer to four species of the genus Cucurbita, also called marrows depending on variety or the nationality of the speaker...
, pumpkin
Pumpkin
A pumpkin is a gourd-like squash of the genus Cucurbita and the family Cucurbitaceae . It commonly refers to cultivars of any one of the species Cucurbita pepo, Cucurbita mixta, Cucurbita maxima, and Cucurbita moschata, and is native to North America...
(both from Cucurbita
Cucurbita
Cucurbita is a genus in the gourd family Cucurbitaceae first cultivated in Mesoamerica and now used in many parts of the world. It includes species grown for their fruit and edible seeds , as well as some species grown only as gourds...
), melon including watermelon
Watermelon
Watermelon is a vine-like flowering plant originally from southern Africa. Its fruit, which is also called watermelon, is a special kind referred to by botanists as a pepo, a berry which has a thick rind and fleshy center...
(Citrullus vulgaris), and cucumber
Cucumber
The cucumber is a widely cultivated plant in the gourd family Cucurbitaceae, which includes squash, and in the same genus as the muskmelon. The plant is a creeping vine which bears cylindrical edible fruit when ripe. There are three main varieties of cucumber: "slicing", "pickling", and...
(Cucumis
Cucumis
Cucumis is a genus of twining, tendril-bearing plants in the Cucurbitaceae family which includes the cucumber, true melons, the horned melon, and Cucumis anguria, the West Indian gherkin...
). The Begoniaceae are known for their horticultural species, of which there are over 130.
Overview
The cucurbitales are an order of cosmopolitan plants with distribution particularly diverse in the tropics. Most are herbs, climber herbs, woody lianas or shrubs but some genus are canopy evergreen lauroideLauraceae
The Lauraceae or Laurel family comprises a group of flowering plants included in the order Laurales. The family contains about 55 genera and over 3500, perhaps as many as 4000, species world-wide, mostly from warm or tropical regions, especially Southeast Asia and South America...
trees. Cucurbitales form an important component of tropical forests from low to montane forests with greater representation in terms of number of species. Although not known with certainty the total number of species in the family, conservative estimates indicate approximately 2.600 species worldwide, distributed in 109 genera. Compared to other plant families, the taxonomy of the family is poorly understood due to their great diversity, difficulty in identifying and reduced taxonomic work done on it.
The order Cucurbitales in the eurosid I clade comprises almost 2600 species in 109 or 110 genera in 8 families, tropical and temperate, of very different sizes, morphology, and ecology. It is a case of divergent evolution
Divergent evolution
Divergent evolution is the accumulation of differences between groups which can lead to the formation of new species, usually a result of diffusion of the same species to different and isolated environments which blocks the gene flow among the distinct populations allowing differentiated fixation...
. In contrast, there is convergent evolution
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...
with other groups not related due to ecological or physical drivers toward a similar solution, including analogous structures.
Some botanical species are trees having similar foliage to the Lauraceae
Lauraceae
The Lauraceae or Laurel family comprises a group of flowering plants included in the order Laurales. The family contains about 55 genera and over 3500, perhaps as many as 4000, species world-wide, mostly from warm or tropical regions, especially Southeast Asia and South America...
due to convergent evolution.
The patterns of speciation in the Cucurbitales is diversified in a high number of species. They have a pantropical distribution with centers of diversity in Africa South America and Southeast Asia. They most likely originated in West Gondwana
Gondwana
In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
and are 67–107 million years old, so the oldest split could relate to the break-up of Gondwana in the middle Eocene to late Oligocene, 45–24 million years ago, and reached their current distribution by multiple intercontinental dispersal events. One factor was product of aridification, others groups responded to favourable climatic periods and expanded across the available habitat, occur as opportunistic species across wide distribution other groups diverged in long time isolated areas.
The order Cucurbitales is composed by the families: Anisophylleaceae
Anisophylleaceae
Anisophylleaceae is a small family with four genera in the order Cucurbitales, according to the APG II. However it is more isolated from the other suprafamilal clades in this order, while it shows some similarities in flower morphology with the genus Ceratopetalum...
, Begoniaceae
Begoniaceae
Begoniaceae is a family of flowering plants with about 1400 species occurring in the subtropics and tropics of both the New World and Old World. All but one of the species are in the genus Begonia. The only other genus in the family, Hillebrandia, is endemic to the Hawaiian Islands and has a single...
, Coriariaceae, Corynocarpaceae, Cucurbitaceae
Cucurbitaceae
The plant family Cucurbitaceae consists of various squashes, melons, and gourds, including crops such as cucumber, pumpkins, luffas, and watermelons...
, Tetramelaceae
Tetramelaceae
Tetramelaceae is a family of plant formerly classed in the Datiscaceae family. It contains the following genera:* Octomeles* Tetrameles...
and Datiscaceae
Datiscaceae
Datiscaceae are a family of Dicotyledonous plants, containing two species of the genus Datisca. Two other genera, Octomeles and Tetrameles are now classified in the Tetramelaceae family....
. Some of the synapomorphies of the order are: leaves in spiral, secondary veins palmated, calyx or perianth valvate, elevated stomatal calyx/perianth with separate styles. The two whorls similar in texture.
Tetrameles nudiflora
Tetrameles nudiflora
Tetrameles nudiflora is a species of plant in the Tetramelaceae family. It is a tree found in Queensland , Bangladesh, Bhutan, China, India, Indonesia, Laos, Malaysia, Burma, Sri Lanka, Cambodia, Thailand, and Vietnam...
is a tree of immense proportions of height and width, Tetramelaceae
Tetramelaceae
Tetramelaceae is a family of plant formerly classed in the Datiscaceae family. It contains the following genera:* Octomeles* Tetrameles...
, Anisophylleaceae
Anisophylleaceae
Anisophylleaceae is a small family with four genera in the order Cucurbitales, according to the APG II. However it is more isolated from the other suprafamilal clades in this order, while it shows some similarities in flower morphology with the genus Ceratopetalum...
and Corynocarpaceae are tall canopy trees in temperate and tropical forest. The genus Dendrosicyos
Dendrosicyos
Dendrosicyos is a monotypic genus in the Cucurbitaceae. The only species is Dendrosicyos socotranus, the cucumber tree. The species is endemic to the island of Socotra in Yemen, and is the only species in the Cucurbitaceae to grow in a tree form.- Features :It has a bulbous trunk and a small crown....
with the only species cucumber tree, is adapted to arid semi desert island of Socotra
Socotra
Socotra , also spelt Soqotra, is a small archipelago of four islands in the Indian Ocean. The largest island, also called Socotra, is about 95% of the landmass of the archipelago. It lies some east of the Horn of Africa and south of the Arabian Peninsula. The island is very isolated and through...
. Deciduous perennial cucurbitales lose all of their leaves
Leaves
-History:Vocalist Arnar Gudjonsson was formerly the guitarist with Mower, and he was joined by Hallur Hallsson , Arnar Ólafsson , Bjarni Grímsson , and Andri Ásgrímsson . Late in 2001 they played with Emiliana Torrini and drew early praise from the New York Times...
for part of the year depending on variations in rain
Rain
Rain is liquid precipitation, as opposed to non-liquid kinds of precipitation such as snow, hail and sleet. Rain requires the presence of a thick layer of the atmosphere to have temperatures above the melting point of water near and above the Earth's surface...
fall. The leaf loss coincides with the dry season
Dry season
The dry season is a term commonly used when describing the weather in the tropics. The weather in the tropics is dominated by the tropical rain belt, which oscillates from the northern to the southern tropics over the course of the year...
in tropical, subtropical and arid regions. In temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
or polar climate
Polar climate
Regions with a polar climate are characterized by a lack of warm summers . Regions with polar climate cover over 20% of the Earth. The sun shines 24 hours in the summer, and barely ever shines at all in the winter...
s the dry season is due to the inability of the plant to absorb water available by to be in the form of ice.
Half of the species know are in the great diverse Begonia group of Begoniaceae with 2 genera, and 1500 species. Because of the lack of worldwide knowledge about the order in general, very little is known about the order diversity. The knowledge of this order to national level, is that to be expected in countries with limited economic means with the vast majority of species indeterminate or even poorly determined. Therefore an increase in the study of order, at national level, is of utmost importance for the progress of the systematics of the order in general. The increase in the number of species is expected for the genera, bringing an expected considerable increase in the total number of species of the family. Before DNA-molecular classifications, the species placed now in eight families of cucurbitales order, was assigned to orders as diverse as Ranunculales
Ranunculales
Ranunculales is an order of flowering plants. Of necessity it contains the family Ranunculaceae, the buttercup family, because the name of the order is based on the name of a genus in that family. Ranunculales belongs to a paraphyletic group known as the basal eudicots...
, Malpighiales
Malpighiales
Malpighiales is one of the largest orders of flowering plants, containing about 16000 species, approximately 7.8% of the eudicots. The order is very diverse and hard to recognize except with molecular phylogenetic evidence. It is not part of any of the classification systems that are based only on...
, Violales
Violales
Violales is a botanical name of an order of flowering plants and takes its name from the included family Violaceae. The name has been used in several systems, although some systems used the name Parietales for similar groupings...
, and Rafflesiales
Rafflesiales
Rafflesiales is a botanical name of an order of flowering plants. The name was first published by Oliver in 1895. The Cronquist system used this name for an order placed in subclass Rosidae with the following circumscription :...
. Early molecular studies revealed several surprises, such as the non-monophyly of the traditional Datiscaceae
Datiscaceae
Datiscaceae are a family of Dicotyledonous plants, containing two species of the genus Datisca. Two other genera, Octomeles and Tetrameles are now classified in the Tetramelaceae family....
, including Tetrameles and Octomeles
Octomeles
Octomeles is a genus of plant in family Datiscaceae. It contains the following species :* Octomeles sumatrana, Miq....
, but the exact relationships among the families remained unclear.
Classification
Under the Cronquist systemCronquist system
The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in his texts An Integrated System of Classification of Flowering Plants and The Evolution and Classification of Flowering Plants .Cronquist's system places flowering plants into two...
, the first four families (including Begoniaceae
Begoniaceae
Begoniaceae is a family of flowering plants with about 1400 species occurring in the subtropics and tropics of both the New World and Old World. All but one of the species are in the genus Begonia. The only other genus in the family, Hillebrandia, is endemic to the Hawaiian Islands and has a single...
, Cucurbitaceae
Cucurbitaceae
The plant family Cucurbitaceae consists of various squashes, melons, and gourds, including crops such as cucumber, pumpkins, luffas, and watermelons...
, and Datiscaceae
Datiscaceae
Datiscaceae are a family of Dicotyledonous plants, containing two species of the genus Datisca. Two other genera, Octomeles and Tetrameles are now classified in the Tetramelaceae family....
), were placed in the order Violales
Violales
Violales is a botanical name of an order of flowering plants and takes its name from the included family Violaceae. The name has been used in several systems, although some systems used the name Parietales for similar groupings...
, within the Dilleniidae, with the Tetramelaceae subsumed within the Datiscaceae. The other families were distributed throughout various orders. The present classification is due to APG II (2003)
Angiosperm Phylogeny Group
The Angiosperm Phylogeny Group, or APG, refers to an informal international group of systematic botanists who came together to try to establish a consensus on the taxonomy of flowering plants that would reflect new knowledge about plant relationships discovered through phylogenetic studies., three...
.