Rye (Secale cereale) is a grass grown extensively as a grain and as a forage crop. It is a member of the wheat tribe (Triticeae) and is closely related to barley and wheat. Rye grain is used for flour, rye bread, rye beer, some whiskies, some vodkas, and animal fodder. It can also be eaten whole, either as boiled rye berries, or by being rolled, similar to rolled oats. Rye is a cereal and should not be confused with ryegrass which is used for lawns, pasture, and hay for livestock. Rye bread, including pumpernickel, is a widely eaten food in Northern and Eastern Europe. Rye is also used to make the familiar crisp bread. Rye flour has a lower gluten content than wheat flour, and contains a higher proportion of soluble fiber. Some other uses of rye include rye whiskey and use as an alternative medicine in a liquid form, known as rye extract. Often marketed as Oralmat, rye extract is a liquid obtained from rye and similar to that extracted from wheatgrass. Its benefits are said to include a strengthened immune system, increased energy levels and relief from allergies, but there is no clinical evidence for its efficacy. Rye seems also active in the prevention of prostate cancer. Rye straw is used to make corn dollies.