Eleocharis parvula
 Eleocharis parvula is a species of spikesedge known by the common names dwarf spikerush small spikerush and hairgrass in aquaria. It has a circumboreal distribution growing throughout Eurasia and North America into Central America. It is a plant of brackish and saltwater habitat such as marshes and mudflats. It is a perennial herb growing tufts of spongy compressible stems not more than 10 centimeters tall.