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).
Cairney, JWG & Meharg, AA (2003). Ericoid mycorrhiza: a partnership that exploits harsh edaphic conditions. European Journal of Soil Science54, 735-740.
Walters, Dick R. and David J. Keil. Vascular Plant Taxonomy. Kendall\Hunt: 1996, Dubuque