Eleocharis acuta (Common Spike-rush)
A quote from "Flora of the A.C.T." Nancy T. Burbidge & Max Gray: "the uppermost leaf sheath thickened, truncate and mucronate at orifice". Mucronate means "ending with a stiff point". The Sample Photos show this feature, which is diagnostic of the species. The drawing below is from that book.
Gallery
Regional distribution
Eleocharis acuta is listed in the following regions:
Map distribution
Eleocharis acuta has been reported at the following locations: