The Alismatales order commonly referred to as water plantain are all water plants. The plants in this order grow underwater aside from the flower that either sits atop the water or barely rising out. Most species will stay underwater until fully grown. Alismatales consists of 165 in 13 families. Some species of this order grow starchy, edible tubers with up to 7% protein content and have the flavor of potatoes. Members of the Lewis and Clark expedition ate some of this species called Sagittaria during their journey. Other species in the Alismatales order contain acrid juices and have medicinal properties that can be so strong as to paralyze a person. Species of this order live in most lakes and rivers shallow enough for light to reach them. Although some of the species can be a problem and contaminate rice fields and mess up the operation of hydroelectric dams they are major sources of plants for water gardens.