Rye is a grass that is grown extensively as a grain, as a cover crop and as a forage crop. It is a member of the wheat tribe (Triticeae) and is closely related to both wheat (Triticum) and barley (Hordeum). Rye grain is used for flour, bread, beer, crispbread, some whiskeys, 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 good source of dietary fiber and contains high levels of phosphorus, potassium, magnesium, and calcium.