Zanthoxylum piperitum

Zanthoxylum piperitum, also known as Japanese pepper or Japanese prickly-ash, is a deciduous aromatic spiny shrub or small tree of the citrus and rue family Rutaceae, native to Japan and Korea.

It is called sanshō (山椒) in Japan and chopi (초피) in Korea. Both the leaves and fruits (peppercorns) are used as aromatics and flavorings in these countries. It is closely related to the Chinese Sichuan pepper, which comes from plants of the same genus.

"Japanese pepper" Z. piperitum is called sanshō (山椒; 'mountain pepper') in Japan, but the corresponding cognate term in Korean, sancho (산초) refers to a different species: Z. schinifolium, known as inuzanshō or 'dog sansho' in Japan.

In Korea, Z. piperitum is called chopi (초피). However, in several regional dialects, notably Gyeongsang dialect, it is also called sancho (산초) or jepi (제피).

"Japanese prickly-ash" has been used as the standard American common name.

The variety Z. piperitum var. inerme Makino, known in Japan as Asakura zanshō are thornless, or nearly so, and have been widely cultivated for commercial harvesting.

The forma Z. piperitum f. pubsescens (Nakai) W. T. Lee, is called teol chopi (털초피) in Korea, and is assigned the English name "hairy chopi".

Its natural range spans from Hokkaido to Kyushu in Japan, southern parts of the Korean peninsula, and Chinese mainland.