(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. Slender rush grows in landscapes, crops, roadsides, and all types of fields. It can grow on both wet and dry sites, in soils consisting mainly of sand or clay. Because of its high tolerance of compacted soils, it can outcompete other plant species in such places, hence the name "path rush". It is native throughout all fifty states of United States, most of Canada, and parts of northern Europe. Juncus is a genus of monocotyledonous flowering plants, commonly known as rushes. It is the largest genus in the family Juncaceae, containing around 300 species. Rushes of the genus Juncus are herbaceous plants that superficially resemble grasses or sedges. They have historically received little attention from botanists; in his 1819 monograph, James Ebenezer Bicheno described the genus as "obscure and uninviting". The form of the flower differentiates rushes from grasses or sedges. The flowers of Juncus comprise five whorls of floral parts: three sepals, three petals (or, taken together, six tepals), two to six stamens (in two whorls) and a stigma with three lobes. The stems are round in cross-section, unlike those of sedges, which are typically somewhat triangular in cross-section. In Juncus section Juncotypus (formerly called Juncus subg. Genuini), which contains some of the most widespread and familiar species, the leaves are reduced to sheaths around the base of the stem and the bract subtending the inflorescence closely resembles a continuation of the stem, giving the appearance that the inflorescence is lateral.