A stoloniferous, tufted, sometimes mat-forming, perennial grass with wiry culms, often with fascicles of shoots at the nodes, arching over and rooting to form long looping stolons. Leaf blades have in-rolled margins but are sometimes flat, with needle-like points, and often painfully pungent. The inflorescence is a spike-like panicle smoothly and compactly cylindrical and with branches closely appressed to the main axis; the spikelets are very dense, cylindrical, narrow and pale. Fruit is an ellipsoid grain.