Rhynchospora gracillima

Rhynchospora gracillima is an annual or short lived perrenial sedge that may grow to be 20–60 cm (0.66–1.97 ft) tall.^[2] The 3-angled culms are smooth and densely tufted. The leaves are shorter than the culms and have stiff hairs. They are up to 1 mm (0.039 in) wide and tips are rough. The bracts have longitudinal grooves and sheath the leaves and culms.^[2]

The inflorescences are loosely branched. They are made of one to three clusters, with the outer flowers borne on longer stems than the central ones. The stems are up to 4 cm (1.6 in) long.^[2] The rays are smooth and often curve upwards. They are by supported by bristled bractlets.^[2] The solitary spikelets are narrow, elongated ovals. They have three or four flowers and long stems. There are seven or eight pale brownish glumes with purplish lines. They overlap and spiral.^[2] There are two stamens and two well-developed style branches per floret.^[3]

The morphology of the spikelets has been studied in more detail in Rhynchospora gracillima subsp. subquadrata. While there are usually seven or eight glumes, some specimens may have many as eleven.^[3] The central glumes (glumes four to nine) are the largest and best developed. They are noticeably spiraled with the internodes being enlarged, curved and flattened in order to accommodate the seeds.^[3] Glumes five to nine usually mature to form seeds, with glumes five, ten and eleven sometimes forming seeds. Glumes one through four are always infertile.^[3]

The fruit is a greyish white nutlet. It is biconvex with deep, wavy ridges.^[2]