|
A large family of dicotyledonous usually shrubby plants, commonly called the heath or heather family, numbering about 3000 species in some 100 genera. It is virtually cosmopolitan in distribution though members are poorly represented in Australia. Ericaceous plants have simple often evergreen leaves that lack stipules and may be reduced to needles, e.g. bell heather (Erica cinerea), or rolled, e.g. cowberry (Vaccinium vitisidaea). The flowers are usually actinomorphic and bisexual and may be borne singly or in racemes. The petals, normally four or five, are usually fused at the base. Over half the described species are in the two genera Rhododendron (about 1200 species) and Erica (about 500 species). Both show unusual distributions, species of Erica being concentrated in South Africa (the Cape heaths number some 450 species) while Rhododendron species are concentrated in the Himalayan foothills and New Guinea. Over half the Rhododendron species are cultivated as ornamentals (the azaleas are included in this genus). Many heaths (Erica) and heathers (Calluna) are also grown as ornamentals. The berries of certain species, notably bilberry (Vaccinium myrtilus) and cranberry (Vaccinium oxycoccus), are valued as food in many areas.
|
