水棘针属（学名：Amethystea）是唇形科下的一个属，为一年生直立草本植物。该属共有水棘针（Amethystea caerulea）等数种，分布于西伯利亚至中国云南。

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).