金鸡纳树（学名：Cinchona，又称作鸡纳树、金鸡勒、奎宁树）为茜草科的一属，约包含25种的物种，树皮和根皮是提取奎宁和奎尼丁的重要工业原料。

一般为常绿小乔木，高度约3米。矩圆状披针形或椭圆状矩圆形的叶片以对生的方式生长，一般有7至12厘米的长度；植物长有乳白色或玫瑰色的筒状小花，长1厘米，末端为裂片披针形，边缘披白色长柔毛，花朵皆是聚伞花序腋生或顶生，常为圆锥花的序式排列，有强烈的气味；蒴果为椭圆形，长度大概为12毫米，有开裂的室间；种子形状细小，有翅作为风媒之用。

西印度苦香树——花朵部分

树皮

Cinchona is a genus of flowering plants in the family Rubiaceae containing at least 23 species of trees and shrubs. They are native to the tropical Andean forests of western South America. A few species are reportedly naturalized in Central America, Jamaica, French Polynesia, Sulawesi, Saint Helena in the South Atlantic, and São Tome & Principe off the coast of tropical Africa. A few species are used as medicinal plants, known as sources for quinine and other compounds.