quality:correction, information:classification
The Ericales are a large and diverse order of dicotyledons. Species in this order have considerable commercial importance including for tea, persimmon, blueberry, kiwifruit, Brazil nuts, argan, and azalea. The order includes trees, bushes, lianas, and herbaceous plants. Together with ordinary autophytic plants, the Ericales include chlorophyll-deficient mycoheterotrophic plants and carnivorous plants. Many species have five petals, often grown together. Fusion of the petals as a trait was traditionally used to place the order in the subclass Sympetalae. Mycorrhizal associations are quite common among the order representatives, and three kinds of mycorrhiza are found exclusively among Ericales. In addition, some families among the order are notable for their exceptional ability to accumulate aluminum. Ericales are a cosmopolitan 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 8,000 species, of which the Ericaceae account for 2,000–4,000 species.