T. palustris may refer to: Tephrocybe palustris, a species of fungus in the family Lyophyllaceae which parasitizes sphagnum moss. Terebralia palustris, the mangrove whelk, a species of brackish-water snail in the family Potamididae. Thelypteris palustris, the marsh fern, native to eastern North America and across Eurasia. Triglochin palustris, Marsh Arrowgrass, a variety of arrowgrass found in damp grassland. Tetraodon palustris, a species of pufferfish in the family Tetraodontidae only found in Mekong basin.