What is "achnatherum"

Achnatherum is a genus of plants which includes several species of needlegrass. Several needlegrass species have been switched between Achnatherum and genus Stipa; taxonomy between the two closely related genera is still uncertain.

Achnatherum hymenoides was useful as an amazing health source to Americans. Achnatherum brachychaetum is best known as a noxious marijuana.