Citrus hystrix. A small evergreen tree or multi-branched shrub with aromatic, glossy green leaves. Fragrant white flowers are followed by tart, wrinkled, green fruit. Compact growth when grown in containers. An essential ingredient in Thai cuisine. Excellent in large container. Grows 6-25' tall by 5-12' wide. Blooms seasonally. Full sun to part shade. Plant in moist, fertile, well-drained soil. Zones 9-11.