Sichuan Peppercorns, also spelled Szechwan and Szechuan, are back after a long absence.
Sichuan pepper (xanthoxylum peperitum) is native to northern China and is not related to black pepper (peper nigrum), which is native to India. This pepper is quite aromatic but not very hot. Before Asian cultures were introduced to chile pepper, Sichuan pepper was used along with ginger to give heat to many dishes. The heat in modern Sichuan cooking comes instead from red chile pepper (capsicum annum), introduced to Asia in the 15th century. Sichuan pepper is still called for in many traditional Chinese recipes.
Until very recently there was a long-standing ban on the importation of this pepper. A couple of years ago the FDA banned the importation of Szechuan (Sichuan) Peppercorns because they were carrying a citrus canker virus. This virus could potentially harm the foliage of citrus crops in the U.S. It was never an issue of harm in human consumption. Recently the USDA and FDA have lifted the ban, provided the peppercorns are heated to around 160 degrees Farenheit (which kills the canker virus) before importation.