蓉草（学名：Leersia oryzoides）为禾本科假稻属下的一个种。

Leersia oryzoides is a species of grass known by the common name rice cutgrass or just cut-grass. It is a widespread grass native to Europe, Asia, and North America and present in many other regions, such as Australia, as an introduced species. This is a rhizomatous perennial grass growing to a maximum height between 1 and 1.5 meters. The leaves are up to about 28 centimeters long and have very rough, minutely toothed edges. The inflorescence is a loose, open array of wavy, hairlike branches bearing rows of spikelets. Each spikelet is a flat fruit with a rough, bristly lemma without an awn, and no glumes. Some of the spikelet branches develop within the sheaths of the leaves and are ****. This grass is sometimes used for erosion control and restoring wetlands.