The radially symmetric flowers of the iridaceae
(iris) family have three sepals, three petals and three stamens. Often the petals and sepals are similar in shape and color, so the flower appears to have six petals. The stamens are generally attached to the sepals. The style is divided into three. Leaves are long and linear, often grass-like, overlapping, and folded along the axis. Plants sprout from bulbs or expanded roots, and the stems are usually erect. The US is home to 22 genera and 132 species, in all areas but less common in the Great Plains. The two largest genera are iris (50 species) and sisyrinchium (41 species).