The plant family Ericaceae (also called the heath family or ericaceous plants) are mostly lime-hating (calcifuge) plants that thrive in acid soils. Many well-known plants of the Ericaceae live in temperate climates, such as cranberry, blueberry, heath, heather, huckleberry, azalea and rhododendron. However, the family also contains many tropical species.
The Ericaceae family consists of herbs, shrubs and trees with leaves that are usually alternate, simple and without stipules, and hermaphrodite flowers. The flowers show considerable variability. The petals are often fused (sympetalous) with shapes ranging from narrowly tubular to funnelform or widely bowl-shaped. The corollas are usually radially symmetrical (actinomorphic) but many flowers of the genus Rhododendron are somewhat bilaterally symmetrical (zygomorphic).
Recent genetic research by the Angiosperm Phylogeny Group has resulted in the inclusion of the formerly recognised families Empetraceae, Epacridaceae, Monotropaceae, Prionotaceae and Pyrolaceae into Ericaceae. Most Ericaceae, except Monotropaceae, Prionotaceae and Pyrolaceae form ericoid mycorrhiza. This symbiotic relationship is considered crucial to the success of members of the family in edaphically stressful environments worldwide (Cairney and Meharg, 2003).