Rhododendren

Rhododendren is a genus of woody flowering plants in the family Ericaceae, commonly known as rhododendrons and azaleas. It includes about 1,000 species of evergreen and deciduous shrubs and small trees. Native to temperate regions of Asia, Europe, and North America, many species occur in the Himalayas and in East and Southeast Asia. The plants are known for their large, showy inflorescences; flowers are usually funnel-shaped or bell-shaped, arranged in panicles or trusses, and display colors ranging white to pink, red, purple, and yellow. Leaves are typically alternate, simple, and leathery; most rhododendrons are evergreen, though some species are deciduous.

Cultivation and habitat: They are widely cultivated as ornamentals in gardens and parks. They prefer acidic, well-drained soils rich in organic matter, with a low to moderate pH (often around 4.5–6.0). They thrive in sheltered locations with partial shade and protection from hot afternoon sun and wind. Pruning is usually done after flowering to maintain shape and size. In poorly drained soils, they are susceptible to root diseases such as Phytophthora.

Toxicity and ecology: All parts contain grayanotoxins, which can be toxic if ingested by humans or animals. Some species have become invasive in parts of Europe, New Zealand, and other regions where they escape cultivation.

Taxonomy and terminology: The genus name Rhododendron derives from Greek words rhodos (rose) and dendron (tree). The term Rhododendren is the plural in several languages; in horticulture, azaleas are generally treated as part of Rhododendron.