Zanthoxylum simulans, the Sichuan pepper, produces brownish red fruits that have a spicy, numbing effect.

Description:
Zanthoxylum simulans, the Sichuan pepper, is a deciduous, aromatic, spiny shrub or small tree with small, yellowish green flowers and brownish red fruits that are used in Sichuan cuisine. The peppercorns impart a strange spiciness that actually numbs the tongue -- a strange and intriguing sensation kind of like crossing a habanero pepper with a trip to the dentist. It's cool. Really! Plants are dioecious with separate male and female plants. Females are partially self-fertile but will produce more fruit in the presence of a male plant. Apparently, the male sansho or Japanese pepper (Z. piperitum) can also pollinate a female Z. simulans. Go figure!