It is sedge. If you smell the underground part you will find it aromatic. It is used in Agarbatti Industries. Also used as medicine and to extract aromatic oil. It is Cyperus sp.
It is Hydra headed. Hence a curse for farmers if it grows in field. Very difficult to manage specially through manual methods. In North Chhattisgarh farmers allow pigs to the field. They consume all the underground parts without any delay. This action pulverizes the soil and through this unique way they get rid from this problematic weed. It is done before sowing of crop.
In summer the Agricultural scientists suggest use of Soil Solarization to destroy dormant underground parts.