A family of monocotyledonous (see monocotyledon) herbs, close to Liliaceae, but with erect, simple stems bearing leaves in an opposite pair, or in a single whorl near the summit of the stem, and having reticulate veining, unusual in monocotyledons. The flowers are terminal, usually solitary, or sometimes in a small umbel, with free sepals and petals each in 1 whorl, and with the parts in either threes or fours. The number of stamens is equal to that of the perianth segments; the ovary is superior, and usually 1-celled. The fruit is a berry or a fleshy capsule. There are 4 genera, with 53 species, in the northern temperate zone. Paris, found in Europe and temperate Asia, has flower parts in fours; Trillium, of N. America, has them in threes.
Subjects: Plant Sciences and Forestry.