noun
helophyte; marsh plant
A technical botanical term for plants that grow in marshes or swamps, with their roots in waterlogged soil but shoots above water.
沼沢植物は湿地帯の生態系で重要な役割を果たしている。
Marsh plants play an important role in the ecosystem of wetlands.
水生植物 (aquatic plants) is a broader category that includes plants living entirely in water, while 沼沢植物 specifically refers to marsh plants rooted in waterlogged soil.
Compound of 沼沢 (marsh, swamp) and 植物 (plant). The exact historical derivation is uncertain, but the term is a straightforward modern botanical compound.