Cyperus acuminatus is a common species of sedge

Cyperus

Cyperus is a large genus of about 600 species of sedges, distributed throughout all continents in both tropical and temperate regions. They are annual or perennial plants, mostly aquatic and growing in still or slow-moving water up to 0.5 m deep. The species vary greatly in size, with small species...

 known by several common names, including tapertip flatsedge and pale umbrella-sedge. This plant is native to North America, where its distribution spans the continent, except northern Canada and southern Mexico. It is found in wet areas from large rivers to roadside ditches. This is an annual plant with a paper-thin stem approaching 40 centimeters in height at maximum. It may have a few thin leaves near the base. Its spherical inflorescence

Inflorescence

An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

 is one to two centimeters wide and contains several spikelets

Raceme

A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...

 each a few millimeters long. Each spikelet has a flat layer of flowers which yield oval-shaped achene

Achene

An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...

fruits, each about one millimeter long.

External links

• Jepson Manual Treatment
• USDA Plants Profile
• Flora of North America
• Photo gallery