(botany) An order of dicotyledonous plants in the subclass Dilleniidae; plants are generally sympetalous with unitegmic ovules and they have twice as many stamens as petals.
An order of flowering plants, division Magnoliophyta (angiosperms), in the large asterid assemblage (often Asteridae in previous systems of classification). Nearly all of the 24 families assigned to the order have previously been considered members of several orders in the subclass Dilleniidae. Ericales are a diverse group that have general asterid characters: tenuinucellate ovules; flowers with fused sepals, and often, fused petals with the anthers fused at least basally to the petals, even when the petals are apparently free; cellular endosperm formation; and tegumentary tapeta.
The largest families are Ericaceae (1350 species), Primulaceae (1000 species), Myrsinaceae (1000 species), Sapotaceae (800 species), and Balsaminaceae (600 species). The two biggest families are largely temperate herbs (Primulaceae), and the next three are largely tropical trees or herbs (Balsaminaceae). A relationship between the first four families has been known for many years, but the last has nearly always been considered related to the rosid family Geraniaceae.
Familiar plants belonging to Ericales include rhododendrons (Rhododendron, Ericaceae), camellias (Camellia, also the genus of tea, Theaceae), primroses (Primula, Primulaceae), phlox (Phlox, Polemoniaceae), and impatiens (Impatiens, Balsaminaceae). See also Blueberry; Dilleniidae; Magnoliopsida; Plant kingdom.
| Ericales | |
|---|---|
| Rhododendron simsii | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Asterids |
| Order: | Ericales Dumort., 1829 |
| Families | |
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The Ericales are a large and diverse order of dicotyledons, including for example tea, persimmon, blueberry, Brazil nut, and azalea. The order includes trees and bushes, lianas and herbaceous plants. Together with ordinary autophytic plants, the Ericales include chlorophyll-deficient myco-heterotrophic plants (e. g. Sarcodes sanguinea) and carnivorous plants (e. g. genus Sarracenia).
Many species have five petals, often grown together. Fusion of the petals is a trait that was traditionally used to place the order in the subclass Sympetalae.[1]
Mycorrhiza is an interesting property, frequently associated with the Ericales. Indeed, the symbiosis with root fungi is quite common among the order representatives, and there are even three kinds of it which can be found exclusively among Ericales (namely, ericoid, arbutoid and monotropoid mycorrhiza). In addition, some families among the order are notable for their exceptional ability to accumulate aluminum (Jansen et al., 2004).
Ericales are a cosmopolitic order. Areas of distribution of families vary largely - while some are restricted to tropics, others exist mainly in Arctic or temperate regions. The entire order contains over 8000 species, of which the Ericaceae account for 2000-4000 species (by various estimates).
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The most profitable plant in the order is tea (Camellia sinensis) from the Theaceae family. The order also includes some edible fruits, including kiwi fruit (Actinidia deliciosa), persimmon (genus Diospyros), blueberry, huckleberry and cranberry, Brazil nut, and Mamey sapote. The order also includes shea (Vitellaria paradoxa), which is the major dietary lipid source for millions of sub-Saharan Africans. Many Ericales species are cultivated for their showy flowers: well-known examples are azalea, rhododendron, camellia, polyanthus, cyclamen, phlox, and busy Lizzie.
The following families are typical of newer classifications. Those marked with an asterisk are recognized in the APG III system.
These make up a basal group of asterids.[2] Under the Cronquist system, the Ericales included a smaller group of plants, which were placed among the Dilleniidae:
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