Juncus tenuis

Juncus tenuis, the slender rush, is a clump-forming, round-stemmed perennial in the Juncaceae (rush family). Slender rush grows to be between 15 and 60 cm tall. Generally considered a weed, it is rarely sold by retailers as a household container plant. Where it is introduced, it is colloquially called path rush, field rush, slender yard rush, poverty rush or wiregrass. The leaves of the plant all come from the base and are not nearly as tall as the stems. The stems are partly covered by sheaths, and have the most distinctive characteristic of the plant on them: clusters or cymes at the top. These cymes consist of branches that have small egg-shaped seed capsules at the end of them. The seeds split into three parts when they become ripe. The plant also spreads via rhizomatous root growth....read more on Wikipedia.