The Cuban wetlands ecoregion blankets the lowland floodplains along Cuba's northern and southern Caribbean shores, with the vast Zapata Swamp of Matanzas and Havana provinces forming its largest expanse and reaching across the Gulf of Batabano. Its habitats grade from permanently and seasonally flooded grasslands dominated by sawgrass and southern cattail into taller swamp forests, with floating aquatics such as fragrant water lily in deeper water and mangroves fringing the seaward margins. As a Neotropical flooded grasslands and savannas system, it is shaped by a tropical wet-and-dry rhythm in which marshy ground sits submerged for much of the year. The region shelters the critically endangered Cuban crocodile, its flagship species, alongside endemic birds including the Zapata wren and Zapata rail, and is classified as critical or endangered despite reserves like the Cienaga de Zapata Biosphere Reserve. For wetland and water gardeners, native genera here include true water lilies and the architectural sawgrass and cattail of permanently wet ground.

The Enriquillo Wetlands ecoregion occupies a low-lying depression in southwestern Hispaniola, straddling both the Dominican Republic and Haiti and centered on a chain of lakes that includes hypersaline Lake Enriquillo, the largest lake in the Caribbean and one whose surface sits roughly 44 meters below sea level. Wetland margins are dominated by salt-tolerant plants such as buttonwood mangrove (Conocarpus erectus), cattails (Typha domingensis), and saltwort (Batis maritima), grading into surrounding dry subtropical thorn forest with guayacán, almácigo, bayahonda, and yarey and Palma cacheo palms. The climate is arid for the tropics, with low annual precipitation in the range of 400 to 500 millimeters and warm water temperatures from about 24 to 29 degrees Celsius, while elevated, sulfurous salinity shapes the lake itself. The wetlands support the island's largest population of the American crocodile (Crocodylus acutus), the critically endangered Ricord's iguana found only around Lake Enriquillo, the rhinoceros iguana, and the endemic Hispaniolan slider turtle, with American flamingos and roseate spoonbills among the birds, and three IUCN category II national parks protect parts of the region. For gardeners in similarly hot, dry settings, native drought-hardy genera of this landscape such as Guaiacum (guayacán) and Bursera (almácigo) point to plants suited to arid, saline-influenced ground.

The Guayaquil flooded grasslands stretch across southwestern Ecuador, centered on the delta and basin of the Guayas River and reaching south to the mangroves of the Gulf of Guayaquil, spanning the provinces of Guayas, Los Ríos, and El Oro. Seasonally flooded grasslands dominate the landscape, interspersed with elements of the neighboring tropical dry forests and laced with riparian flora, while scattered trees include balsa, Jamaica cherry, West Indian elm, and trumpet, and open water carries floating plants such as water hyacinth and pickerelweed. The climate is equatorial with a pronounced dry season, drawing most of its rain during a brief wet period concentrated around the early months of the year. The ecoregion shows low endemism but holds notable wildlife, with the Peruvian tern as its flagship species alongside horned screamers, wood storks, and the endangered equatorial dog-faced bat. It is classified as Critically Endangered, with the great majority of its natural habitat converted to agriculture and aquaculture amid rapid urbanization and recurring El Niño disturbance.

The Orinoco Wetlands ecoregion lies in northeastern Venezuela, just north of the Orinoco River delta, where it forms seven separate patches of flooded grassland embedded in a matrix of mangroves, swamp forest, moist forest, and llanos savanna. Its core is tropical tall flooded grassland with few shrubs or trees, threaded with grasses and sedges such as Paspalum and Rhynchospora and dotted with palm stands including the moriche palm (Mauritia flexuosa), acai (Euterpe oleracea), and Manicaria. The climate is tropical and consistently wet, with annual rainfall ranging between roughly 1,000 and 2,000 millimeters and warm temperatures year-round. The wetlands support notable threatened wildlife, including the giant otter, the Orinoco crocodile, jaguar, and harpy eagle, though oil extraction and dam construction pose growing pressures. For gardeners drawn to tropical, water-loving plantings, this is home country to ornamental palms such as the fan-leaved moriche palm and the clumping acai.

The Pantanal is a vast lowland floodplain centered on the Paraguay River, spanning the Brazilian states of Mato Grosso do Sul and Mato Grosso and reaching into Bolivia and Paraguay. It holds the world's largest tropical wetland and largest flooded grasslands, where vegetation forms a mosaic that blends Brazilian cerrado savanna, Amazonian, Chaco, and semiarid woodland communities; grasses and aquatic plants dominate the seasonally inundated flats while gallery and semideciduous forests occupy the slightly higher ground. The climate is tropical wet-and-dry, and during the rainy season roughly 80 percent of the region is submerged, a flood pulse that shapes habitat structure and species behavior through the year. This near-pristine but only lightly protected ecoregion supports an exceptional concentration of wildlife, including the largest jaguars on the continent, giant otters, marsh deer, and hyacinth macaws. For water gardeners, its native aquatic flora features familiar floating ornamentals such as water hyacinth and water lettuce.

The Paraná flooded savanna stretches along the floodplains of the middle and lower Paraná River and its major tributary the Paraguay River, running through Argentina and Paraguay from Resistencia in Chaco south to the Paraná Delta and the Río de la Plata basin near Buenos Aires. Its low, flood-prone islands and riverbanks carry narrow strips of forest and shrub dominated by sauce criollo (Salix humboldtiana), Tessaria integrifolia, and the red-flowered ceibo (Erythrina crista-galli), interlaced with aquatic flora such as water hyacinths (Eichhornia), giant Victoria cruziana waterlilies, bulrush, and southern cattail (Typha). The permanent presence of large bodies of water creates high humidity that softens daily and seasonal temperature extremes, giving the region a humid subtropical character. The flagship species is the marsh deer, South America's largest deer and listed as vulnerable, alongside capybara, neotropical otter, and more than 300 fish species; the World Wildlife Fund nonetheless rates the ecoregion Critical/Endangered because most of its habitat has been converted to farmland and urban development. For gardeners, several of its natives are familiar ornamentals, including the cockspur coral tree (Erythrina crista-galli) and the showy Victoria cruziana giant waterlily.