Common name: Chinese pepper, Sichuan pepper, Chinese prickly ash, flatspine prickly ash
Zanthoxylum simulans is a deciduous large shrub or small tree native to Asia. It produces the edible Sichuan pepper (along with other Zanthoxylum species). It has even bigger thorns that Z. schinifolium and is found in several beds near the Stone Garden.
Leaves and berry photos by Krzysztof Golik, via Wikimedia Commons
Thorn close-up from Plant Image Library from Boston, via Wikimedia Commons