Diarrhena (beakgrain) is a genus of Asian and North American plants in the grass family. Species 1. \n* Diarrhena americana P. Beauv. - east-central United States (OK MO AR IL IN OH KY TN AL GA NC VA WV MD PA) 2. \n* Diarrhena fauriei (Hack.) Ohwi - Shandong, Jilin, Heilongjiang, Liaoning, Japan, Korea, Primorye 3. \n* Diarrhena japonica Franch. & Sav. - Japan, Jeju-do, Kuril, Jilin, Heilongjiang, Liaoning 4. \n* Diarrhena mandshurica Maxim. - Jilin, Heilongjiang, Liaoning, Primorye, Amur, Khabarovsk, Korea, Hebei, Shanxi 5. \n* Diarrhena obovata (Gleason) Brandenburg - Ontario, east-central United States (TX OK KS NE SD MN IA MO AR IL WI MI IN OH KY TN VA WV PA NY)formerly included