The eudicotyledons They are one of the groups of plants of the Tracheophyta phylum, highly diversified with an approximate of 167,247 species that correspond to 71.5% of the angiosperms (flowering plants). Eudicotyledons are also known as tricolpadas and include oaks, roses, mustard, cacti, blueberries, or sunflowers, among others..
The characteristic features in general of this group of plants include both herbal and woody species. In this group can be located the most common plants with leaves that are wider than long, reticulated venation, variable shape, persistent root system, flowers with well-differentiated sepals and petals, and most importantly, seeds with two cotyledons..
Some data derived from molecular studies indicate that some dicots (such as magnolias and laurels) could be more related to monocotyledonous plants than to the rest of dicots..
In fact, the term eudicotyledons "true dicots" are dicotyledonous plants not related to the Magnoliidae, such as Lauraceae, Myristicaceae, Anonaceae, Magnoliaceae or Canellaceae, among others..
However, changes are continually being made based on molecular studies as science advances. But, for convenience, we are still talking about dicots..
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The eudicotyledons are both herbaceous and woody plants, such as tomato and walnut, respectively.
One way to identify these plants is by cutting across the stem; When doing this, it will be possible to observe in the microscope that the vascular bundles are arranged in a whorl or ring.
The roots or radical system of these plants is formed by persistent primary roots and not by fibrous roots.
The leaves of these plants have a variable shape, although in general their leaves are wider than they are long (unlike monocots). Another distinguishable characteristic is that its leaves have reticular veins..
The flowers generally come in multiples of four or five. On the other hand, it is also possible to clearly differentiate sepals and petals.
Pollen grains are tricolpated or derived from grains of this style. Certainly, this is the determining trait of eudicots (dicots with tri-fold pollen).
According to this, the eudicotyledons could have arisen about 121 million years ago, since the tricolped grains that were first recognized come from that time close to the mid-late Barremian..
The seeds have two cotyledons, and in their mature state they lack endosperm since this is absorbed by the cotyledons. In fact, a newly germinated eudicotyledonous plant is completely dependent on the nutrients stored in the cotyledons..
The most important orders of the eudicotyledons or tricolpates are:
It includes some 5,628 species of the families Berberidaceae, Circaeasteraceae, Eupteleaceae, Lardizabalaceae, Menispermaceae, Papaveraceae, Ranunculaceae.
The features of this order are pieces of the gynoecium as opposed to those of the perianth, which is bare once the fruit is formed. The vascular bundles are separated, vessels present only in the central part, they have true tracheids, and some species have fluorescent wood. They produce flavonoids.
They are composed of plants that have stipules around the stem. For each carpel there are 1 to 2 ovules, the endosperm is poorly developed, and the embryo is long.
They have about 1860 species and include the families Nelumbonaceae, Platanaceae, Proteaceae, and Sabiaceae.
They have spiral leaves, webbed secondary veins, with a valved calyx, raised stomata, and separate styles..
It is composed of the families Anisophylleaceae, Apodanthaceae, Begoniaceae, Coriariaceae, Corynocarpaceae, Cucurbitaceae, Datiscaceae, Tetramelaceae. Contains about 3027 species.
It has about 6238 species and includes the families Anacardiaceae, Biebersteiniaceae, Burseraceae, Kirkiaceae, Meliaceae, Nitrariaceae, Rutaceae, Sapindaceae, Simaroubaceae, Tetradiclidaceae.
Sapindales have two whorls of stamens, they have a nectariferous disc with variable position. Its habit is woody, the flowers are pentameric and its ovary is superb. The flowers are grouped in cyymos inflorescences.
The leaves are spirally arranged, serrated and have a simple vein.
It comprises about 13240 species and groups the families Actinidiaceae, Balsaminaceae, Clethraceae, Cyrillaceae, Diapensiaceae, Ebenaceae, Ericaceae, Fouquieriaceae, Lecythidaceae, Marcgraviaceae, Mitrastemonaceae, Pentaphylacaceae, Polemoniaceae, Primulaceae, Roridulaceae, Sapotameriaceae, Sladenraceniaceae, Sardenraceniaceae, Sapotameriaceae, Sardenraceniaceae, Sladenraceniaceae, Theaceae.
This order has about 6984 species and includes the families Bixaceae, Cistaceae, Cyrtinaceae, Diegodendraceae, Dipterocarpaceae, Malvaceae, Muntingiaceae, Neuradaceae, Sarcolaenaceae, Sphaerosepalaceae, Thymelaeaceae.
The flowers of these plants are hypoginous, gamocarpellar, dialipetal. While the leaves are palmatinervias and are sometimes compound.
They are species whose flowers are dialipetal, syncarpic, with an evident perianth, and possess the enzyme myrosinase, which synthesizes sulfur compounds.
It comprises some 3,760 species, and groups the families Akaniaceae, Bataceae Brassicaceae, Bretschneideraceae, Capparaceae, Caricaceae, Cleomaceae, Emblingiaceae, Gyrostemonaceae, Cleomaceae, Emblingiaceae, Gyrostemonaceae, Koeberliniaceae, Limnanthaceae, Moringaceae, Pentadiplandraceae, Salvadoralaceaceae.
This order comprises about 35326 species and groups the families Alseuosmiaceae, Argophyllaceae, Asteraceae, Calyceraceae, Campanulaceae, Goodeniaceae, Menyanthaceae, Pentaphragmataceae, Phellinaceae, Rousseaceae, Stylidiaceae.
The most common characteristics are that they have spirally arranged leaves, a valvated corolla, and the stamens are closely united, forming a kind of tube around the style. The ovary is inferior and the pollen is trinucleated.
They have leaves with serrated margins, flowers grouped in cymeus inflorescence, they have nectariferous hypanthos, a dry stigma and the calyx remains after the formation of the fruit. Endosperm is scant or absent.
It comprises some 9508 species, and groups together the families Barbeyaceae, Cannabaceae, Dirachmaceae, Elaeagnaceae, Moraceae, Rhamnaceae, Rosaceae, Ulmaceae and Urticaceae.
It has about 2579 species and includes the families Altingiaceae, Aphanopetalaceae, Cercidiphyllaceae, Crassulaceae, Cyomoriaceae, Daphhniphyllaceae, Grossulariaceae, Haloragaceae, Hamamelidacae, Iteaceae, Paeoniaceae, Penthoraceae, Peridiscaceae, Texaecarpagaceae.
Some characteristics are that they have basifix anthers, sagitate transversely, the carpels are free, the stigmas are decurrent and the dried fruits.
It includes some 1,599 species of the families Betulaceae, Casuarinaceae, Fagaceae, Juglandaceae, Myricaceae, Nothofagaceae, Ticodendraceae.
They are plants that are generally associated with ectomycorrhizae, have scales on the buds, the margin of the leaves toothed, monoecious species, do not have nectaries, the flowers are staminate and are grouped in spikes or catkins..
The androecium has carpellar flowers with decurrent, linear and dry stigma. They develop large nuts and cotyledons.
It has about 13,822 species and includes the families Alzateaceae, Combretaceae, Crypteroniaceae, Lythraceae, Melastomataceae, Myrtaceae, Onagraceae, Penaeaceae, Vochysiaceae.
These plants have scaly bark, simple, whole leaves. Its flowers are tetrameric, with welded styles, they present many ovules, and its floral receptacle has a concave-tubular shape. The seeds have a fairly developed endosperm.
Other important orders are the Geraniales, Fabales, Gunnerales, Lamiales, Solanales and Malpighiales..
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