Diarrhena

{{Short description|Genus of grasses}}

{{Automatic taxobox

|image = Diarrhena americana HC-1950.jpg

|image_caption = Diarrhena americana1950 illustration from USDA-NRCS PLANTS Database / Hitchcock, A.S. (rev. A. Chase). 1950. Manual of the grasses of the United States. USDA Miscellaneous Publication No. 200. Washington

|display_parents = 2

|taxon = Diarrhena

|authority = P.Beauv.

|type_species = Diarrhena americana

|type_species_authority = P.Beauv.

|synonyms_ref = [http://apps.kew.org/wcsp/namedetail.do?name_id=470200 Kew World Checklist of Selected Plant Families]

|synonyms =

• Diarina Raf.
• Korycarpus Zea ex Lag.
• Corycarpus Zea ex Spreng., alternate spelling
• Roemeria Roem. & Schult. 1817, illegitimate homonym not Medik. 1792 (Papaveraceae) nor Raddi 1818 (liverwort in Aneuraceae) nor Moench 1794 (Amaranthaceae) nor Thunb. 1798 (Sapotaceae) nor DC. 1821 (Capparaceae)
• Neomolinia Honda & Sakisaka

}}

Diarrhena, or beakgrain, is a genus of Asian and North American plants in the grass family.[https://www.biodiversitylibrary.org/page/394221#page/226/mode/1up Palisot de Beauvois, Ambroise Marie François Joseph. 1812. Essai d'une Nouvelle Agrostographie 142-143] in Latin[https://www.biodiversitylibrary.org/page/394221#page/310/mode/1up Palisot de Beauvois, Ambroise Marie François Joseph. 1812. Essai d'une Nouvelle Agrostographie plate XXV (25), figure XI (11)] line drawings of Diarrhena americana[http://www.tropicos.org/Name/40029297 Tropicos, Diarrhena P. Beauv.]

; Species[http://www.theplantlist.org/tpl1.1/search?q=Diarrhena The Plant List search for Diarrhena][http://bonap.net/NAPA/TaxonMaps/Genus/County/Diarrhena Biota of North America Program 2013 county distribution maps]

• Diarrhena americana P. Beauv. - east-central United States (OK MO AR IL IN OH KY TN AL GA NC VA WV MD PA)
• Diarrhena fauriei (Hack.) Ohwi - Shandong, Jilin, Heilongjiang, Liaoning, Japan, Korea, Primorye
• Diarrhena japonica Franch. & Sav. - Japan, Jeju-do, Kuril, Jilin, Heilongjiang, Liaoning
• Diarrhena mandshurica Maxim. - Jilin, Heilongjiang, Liaoning, Primorye, Amur, Khabarovsk, Korea, Hebei, Shanxi
• 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

see Ammophila Catabrosa Cutandia Sphenopus Vulpia

{{columns-list|colwidth=30em|

• Diarrhena aquatica - Catabrosa aquatica
• Diarrhena divaricata - Sphenopus divaricatus
• Diarrhena festucoides Raspail 1825 not (Raf.) Fernald 1932 - Cutandia divaricata
• Diarrhena littoralis - Ammophila arenaria subsp. australis
• Diarrhena maritima - Cutandia maritima
• Diarrhena setacea - Vulpia octoflora}}