Cattails are planted extensively in Lorong Halus wetland for the sole purpose of cleaning the water that is piped from the reservoir. There is one species of Cattail that grows naturally in Singapore. Cattails are unique in that their leaves grow vertically and their roots also grow deep, so they can help purify water. More details of the local Cattail can be found http://www.naturia.per.sg/buloh/plants/cattail.htm.