Panicum

{{Short description|Genus of grasses}}

{{Automatic taxobox

|image = Panicum virgatum.jpg

|image_caption = P. virgatum

|display_parents = 4

|taxon = Panicum

|authority = L.

|synonyms_ref = {{cite POWO |id=1194715-2 |title=Panicum L. |access-date=2 June 2025}}

|synonyms =

• Aconisia J.R.Grande
• Arthragrostis Lazarides
• Chasea Nieuwl.
• Eatonia Raf.
• Eriolytrum Desv. ex Kunth, not validly publ.
• Monachne P.Beauv.
• Phanopyrum (Raf.) Nash
• Polyneura Peter 1930, illegitimate homonym not Kylin 1924
• Psilochloa Launert
• Talasium Spreng.
• Yakirra Lazarides & R.D.Webster

}}

Panicum (panicgrass){{PLANTS|id=PANIC|taxon=Panicum|access-date=15 May 2015}} is a large genus of about 250 species of grasses native throughout the tropical regions of the world, with a few species extending into the northern temperate zone. They are often large, annual or perennial grasses, growing to {{cvt|1|–|3|m|ft|0}} tall.[https://www.biodiversitylibrary.org/page/9308504#page/169/mode/1up Freckmann, R. W. & M. G. Lelong. 2002. Nomenclatural changes and innovations in Panicum and Dichanthelium (Poaceae: Paniceae)]. Sida 20(1): 161–174Valdes, B. & H. Scholz. 2006. "The Euro+Med treatment of Gramineae - a generic synopsis and some new names". Willdenowia 36(2): 657–669

The flowers are produced in a well-developed panicle often up to {{cvt|60|cm}} in length with numerous seeds, which are {{cvt|1|–|6|mm|2}} long and {{cvt|1|–|2|mm|2}} broad. The fruits are developed from a two-flowered spikelet. Only the upper floret of each spikelet is fertile; the lower floret is sterile or staminate. Both glumes are present and well developed.Flora of China [http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=123762 Vol. 22 Page 504 黍属 shu shu Panicum Linnaeus, Sp. Pl. 1: 55. 1753. ][http://www.efloras.org/florataxon.aspx?flora_id=5&taxon_id=123762 Flora of Pakistan][http://luirig.altervista.org/flora/taxa/floraspecie.php?genere=Panicum Altervista Flora Italiana, genere Panicum] includes photos and distribution maps of several species[http://bonap.net/NAPA/TaxonMaps/Genus/County/Panicum Biota of North America Program 2013 county distribution maps]Valdés-Reyna, J., F. O. Zuloaga, O. Morrone & L. Aragón Melchor. 2009. [http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0366-21282009000100006 "El género Panicum (Poaceae: Panicoideae) en el noreste de México".] Boletín de la Sociedad Botánica de México 84: 59–82.Morrone, O., A. M. Antón & F. O. Zuloaga. 1995. "Axonopus". Flora Fanerogámica Argentina. 19(1): 11–16

Australia has 29 native and 9 introduced species of Panicum.Grasses of the Tweed Valley of NSW: An introductory field guide to locally common grasses: native and introduced, compiled by Penny Watsford, Nullum Publications, 2004 {{ISBN|0-9756823-0-X}})[http://ausgrass2.myspecies.info/content/panicum-0 Ausgrass2, Grasses of Australia]{{Cite web |url=http://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:apni.taxon:411937#tab_classification |title=Atlas of Living Australia |access-date=2015-02-02 |archive-url=https://web.archive.org/web/20160527034556/http://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:apni.taxon:411937#tab_classification |archive-date=2016-05-27 |url-status=dead | publisher = Atlas of Living Australia }}

Well-known species include P. miliaceum (proso millet) and P. virgatum (switchgrass).

Phylogenetic studies found the genus as previously circumscribed was polyphyletic, and several species have been reassigned to other genera. Most species in section Stolonifera of subgenus Phanopyrum were transferred to Ocellochloa, while P. venezuelae was placed in the new monotypic genus Drakkaria.Christian Silva, Júlia da Costa Hillmann, Juan Manuel Acosta, Reyjane Patrícia Oliveira, Fernando Omar Zuloaga, One more step into the resolution of Panicum (Poaceae) polyphyly: Drakkaria, a new segregate genus from neotropical Seasonally Dry Tropical Forests, Botanical Journal of the Linnean Society, Volume 207, Issue 3, March 2025, Pages 208–224, https://doi.org/10.1093/botlinnean/boae044