Editing Marsh (section)

====Playa lakes====
[[Playa lake]]s are a form of shallow freshwater marsh in the southern high plains of the United States.<ref>Smith, L. M. 2003. Playas of the Great Plains. Austin, TX: University of Texas Press.</ref> Like vernal pools, they are only present at certain times of the year and generally have a circular shape.<ref>{{cite web|last=United States Environmental Protection Agency|title=Playa Lakes|url=http://water.epa.gov/type/wetlands/playa.cfm|access-date=5 February 2012|url-status=live|archive-url=https://web.archive.org/web/20120204144636/http://water.epa.gov/type/wetlands/playa.cfm|archive-date=4 February 2012}}</ref> As the playa dries during the summer, conspicuous plant zonation develops along the shoreline.<ref>Bolen, E. G., Smith, L. M., and Schramm, H. L., Jr. 1989. Playa lakes: prairie wetlands of the southern High Plains. BioScience 39: 615–23.</ref>