Rhododendroideae

Rhododendroideae is a subfamily within the plant family Ericaceae. In many classification schemes, it comprises the genus Rhododendron and closely related genera; the precise composition has shifted with advances in molecular phylogenetics. The type genus is Rhododendron; azaleas are commonly treated as belonging to Rhododendron, and many widely cultivated ornamental plants are included in this group.

Rhododendroideae members are predominantly shrubs or small trees. Leaves are generally simple, alternate, and often evergreen with a leathery texture; deciduous species occur in some lineages. The flowers, produced in large terminal or axillary clusters, are typically bell- or funnel-shaped with five petals and a wide range of colors. Flowering is often showy and conspicuous in late spring to summer.

The subfamily has a wide native distribution in temperate and montane regions of Asia, Europe, and North America, with centers of diversity in the Himalayas, East Asia, and parts of North America. They commonly inhabit acidic, well-drained soils and may occur in forest understories, heathlands, or subalpine habitats.

Rhododendroideae species play roles in native ecosystems as sources of nectar and cover. They are widely cultivated for ornamental horticulture, with numerous cultivars and garden hybrids representing evergreen and deciduous forms. Some species show tolerance to various climates, while others require specific soil conditions.

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