What is "amethystea"

Amethystea is a genus of plants in the Lamiaceae, first described for modern science by Linnaeus in 1753. It has only one known species, Amethystea caerulea, native to China, Japan, Korea, Central Asia ( Tibet, Xinjiang, Kazakhstan, Tajikistan, Kyrgyzstan), and parts of Russia ( Altai, Chita, Irkutsk, Buryatiya, Primorye).