Trillium, common and generic name of a perennial plant of the Trilliaceae family (sometimes classified as a subfamily of the lily family). The name derives from the arrangement of leaves, petals and sepals in groups of 3. The plant grows in clusters. It has a short, tuberlike rootstock and a fleshy stalk bearing a whorl of 3 leaves near the top. A single flower is produced in spring. The fruit is a red berry. Of the 40 species known worldwide, about 30 are American, the remainder Asiatic. Five species are native to Canada. Trillium grandiflorum (white trillium, white lily, wakerobin) flowers Apr-May in the hardwood forests of western and central Québec and in the lower Ottawa Valley, Ont. It has been the Provincial Floral Emblem in Ontario since 1937. The roots were valued for their astringent and antiseptic properties.