Common name: Cogon grass, Cotton grass, Thatch grass • Hindi: उलू Uloo, सिऱू Sirhu, Dabh, Khans • Manipuri: ইমোম Imom • Bengali: ঊলূ Ooloo • Kannada: Sannadabbai hullu • Telugu: Balbajamu • Marathi: दूब Dub • Sanskrit: दर्भ Darbha
Botanical name: Imperata cylindrica Family: Poaceae (grass family)
Cogon grass is a perennial rhizomatous grass native to east and southeast
Asia, India, Micronesia and Australia. It grows from 0.6-3 m (2-10 feet) tall.
The leaves are about 2 cm wide near the base of the plant and narrow to a
sharp point at the top; the margins are finely toothed and are embedded with
sharp silica crystals. The main vein is a lighter colour than the rest of the
leaf and tends to be nearer to one side of the leaf. The upper surface is
hairy near the base of the plant while the underside is usually hairless.
Roots are up to 1.2 meters deep, but 0.4 m is typical in sandy soil.
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 later assists the wind-dispersed seed in
drifting through the air. Cogon grass ranks number seven on the list of the
world's worst weeds.
Identification credit: R.K. Nimai Singh
|Photographed in Imphal,