However, as botanists have come to understand the rhododendrons better, they have discovered that habit (tree or shrub) and flower size are not such important features. Today rhododendrons are distinguished according to leaf size, and divided into the large-leafed evergreen rhododendrons (shinan in Chinese), and the azaleas whose leaves grow large in spring but are shed in autumn to be replaced by small leaves.
但隨著人們對杜鵑瞭解越多，發現兩者樹型、花大小並無一定，今天學者以大葉、小葉區分，常綠性、葉片巨大的是躑躅類（石楠）；春天開大葉、秋天落葉後代之以開小葉的是杜鵑類。杜鵑讓人剪不斷，理還亂，連分類學者都深感困惑。