Orchideae : one of the most well-defined families of plants in the vegetable world, chiefly perennial, herbaceous and epiphytic. The flowers are very irregular, the perianth being formed of three sepals and three petals, the lowest of the petals being often very different in shape and markings from the rest, and called the labellum or lip; both sepals and petals are often richly colored. There is usually one stamen. They are more prized for their beauty than for dietetic or medicinal properties.