Phalaris caroliniana is a species of grass known by the common names Carolina canarygrass and maygrass. It is native to the southeastern United States, and it can be found as a naturalized species along the southern half of the United States to the west coast, as well as northern Mexico and parts of Europe and Australia. It is most often found in moist to wet habitat, such as marshy meadows, and it can thrive in disturbed areas. It is an annual grass reaching a maximum height between 1 and 1.5 meters. The hairy inflorescence is roughly oval in shape and up to 7 centimeters long by 2 wide.