Poaceae are dominant are estimated to constitute 40.5% of the land area of the Earth, excluding Greenland and Antarctica. Grasses are also an important part of the vegetation in many other habitats, including wetlands, forests and tundra. The Poaceae are the most economically important plant family, providing staple foods from domesticated cereal crops such as maize, wheat, rice, barley, and millet as well as forage, building materials (bamboo, thatch, straw) and fuel (ethanol). Though they are commonly called "grasses", seagrasses, rushes, and sedges fall outside this family. The rushes and sedges are related to the Poaceae, being members of the order
Organisms involved in water purification found is very wide but may include species of the following genera: Organisms involved in water purification Most organisms involved in water purification originate from the waste, wastewater or water stream itself or arrive as resting spore of some form from the atmosphere. In a very few cases, mostly associated with constructed wetlands, specific organisms are planted to maximise the efficiency of the process. Biota are an essential component of most sewage treatment processes and many water purification systems. Most of the organisms involved are derived from the waste, wastewater or water stream itself or from the atmosphere or soil