Zizania texana, Texas wild rice, is a plant that is endemic to Texas and is found only on the upper San Marcos river, Hays County. The plant is a member of the same family as commercially sold wild rice. It normally grows 1-2 metres long, but in some cases the stems reached over 5 metres in length. The ribbon-like leaves can be up to a metre long. There are 140 clumps of this plant left in its population - this plant is threatened by the loss and degradation of its habitat. In the 1930s it was so common in the area that it had been regarded as a nuisance. However, the Edward's Aquifer had been drained from a lot of it's water for agricultural use, lowering the flow of water through the San Marcos river. The rice is a rare plant due to various factors affecting its growth. An introduced mammal, the nutria (aka coypu), typically feeds on and destroys it.