Wetland Communities - Floodplain Marsh

View of floodplain marsh along the Myakka River, Myakka River State Park, Sarasota County, Florida. Note the dominance of paragrass, barnyard grass and swamp mallow.

Floodplain marshes are typically associated with floodplain swamps along rivers and streams. These are natural features influenced by overflow and inundation from a flood event. Floodplain marshes are both wetlands and surface waters and are typically flooded for a portion of the growing season. Look for hydrologic indicators during dry periods such as rafted debris, elevated lichen lines, adventitious rooting, river wash, sediment deposition and stain lines. Often the ordinary high water line (OHWL) can be determined by observing the elevation of hydrologic indicators. When gauge data is available the mean annual flood can be calculated and used as an approximation of the OHWL. As their name would indicate floodplain marshes are important landscapes that help alleviate the disastrous effects of flooding and provide important habitat for many wetland dependent species. See illustrated plant ID cards for common plants.

The following is a list of the common plants associated with floodplain marshes in south Florida.

Groundcover

Botanical name	Common name	DEP status
Acrostichum danaeifolium	leather fern	OBL
Aeschynomene sp.	jointvetch	FACW, OBL
Amaranthus australis	southern amaranth	OBL
Aster carolinianus	climbing aster	OBL
Blechnum serrulatum	swamp fern	FACW
Brachiaria mutica	para grass	UPL
Canna flaccida	bandanna of the Everglades	OBL
Carex gigantea	large sedge	OBL
Crinum americanum	swamp lily	OBL
Cynodon dactylon	bermudagrass	UPL
Cyperus sp.	flatsedge	OBL, FACW
Echinochloa crus-galli	barnyardgrass	FACW
Echinochloa walteri	coast cockspur	FACW
Eleocharis baldwinii	Baldwin's spikerush	OBL
Hibiscus grandiflorus	swamp rosemallow	OBL
Hydrochloa caroliniensis	watergrass	OBL
Hydrocotyle ranunculoides	floating penny-wort	OBL
Hymenachne amplexicaulis	trompetilla	OBL
Hymenocallis crassifolia	spider lily	OBL
Juncus repens	lesser creeping rush	OBL
Justicia angusta	pineland waterwillow	OBL
Limnobium spongia	frogbit	OBL
Ludwigia leptocarpa	anglestem primrosewillow	OBL
Ludwigia palustris	marsh seedbox	OBL
Ludwigia peruviana	Peruvian primrosewillow	OBL
Ludwigia repens	creeping primrosewillow	OBL
Panicum dichotomiflorum	fall panicum	FACW
Panicum hemitomon	maidencane	OBL
Panicum rigidulum	red-top panicum	FACW
Paspalum repens	water paspalum	OBL
Polygonum sp.	smartweed	OBL
Proserpinaca palustris	marsh mermaidweed	OBL
Rumex verticillatus	swamp dock	FACW
Sagittaria lancifolia	bulltongue arrowhead	OBL
Scirpus cubensis	Cuban bulrush	OBL
Sesbania emerus	danglepod	FAC
Thalia geniculata	fire flag	OBL
Typha sp.	cattail	OBL
Woodwardia virginica	chainfern	FACW