A grass grown extensively as a grain and forage crop. It is a member of the wheat tribe and is closely related to barley and wheat, although it is the singular species in the genus Secale. Rye grain is used to make flour, feed, some whiskeys and most vodkas.

Rye, alone or overseeded, is planted as a livestock forage or harvested for hay. It is highly tolerant of soil acidity and is more tolerant of dry and cool conditions than wheat, though not as tolerant of cold as barley.