Cogongrass, Imperata cylindrical (L.) Beauv., is a bright chartreusey yellow-green perennial grass that grows 2-4 ft tall and forms dense stands excluding other plant species. The erect leaf blades are about 0.5 in wide and have a prominent whitish off-center midrib and a sharp tip. The leaves are flat and have saw-like edges lined with sharp microscopic silica crystals. The round leaf bases are sheathed and attached to short round stems. The upper part of the leaf blade is hairy near the base, but the underside is smooth. As the plants go dormant, the leaves turn grey-brown from the tips downward, giving the clumps a bronzy gold winter color. The dead leaves remain standing and resist decay. Cogongrass roots are sharp-pointed white barbwire-like rhizomes that branch readily and rapidly shoot out from one plant to form another, sometimes going right through the roots of intervening plants. Most of these rhizomes are interwoven in a dense mat within about a foot of the soil surface, but some may reach as deep as 3-6 ft. Cogongrass flowers are borne in conspicuous cylindrical silky white spikes 1-16 in long and 0.25-1 in in diameter. Each individual flower spikelet has two stamens and two feathery stigmas and is attached to a fuzzy plume that  assists the wind-dispersed seed in drifting through the air.

See the University of Georgia's Cogongrass Web Site for pictures and more detailed information.