Citrus hystrix

Native to tropical Asia and parts of the western Pacific, this thorny evergreen shrub or small tree produces aromatic leaves and fruit. Its leathery, aromatic leaves have such broadly winged stalks that each leaf appears to consist of two joined blades. Small, fragrant white flowers grow singly or in compact clusters, followed by rounded or egg-shaped fruits with conspicuously wrinkled, bumpy rinds. The fruit turns yellow at full maturity, and its sparse pulp is very sour and slightly bitter. The pungent leaves are used in Thai and Indonesian cooking, while the aromatic rind is added to curry pastes. Photographed in Florida.