Family Monotropaceae is a small family of flowering plants that includes the genera Monotropa, Hypopitys and Pityopus. These plants are commonly referred to as Indian pipes, ghost pipes or monotropes. Indian pipe is a reference to the white color of the flowers and the stem, which resembles a pipe. Ghost pipes are named because they lack chlorophyll and do not photosynthesize. Monotropes means 'one turn' in Greek, referring to the spiral arrangement of the flowers on the stem. Other synonyms for family Monotropaceae include the names Ericaceae, Monotropoidae and Sarcodes, which were used in the past but are no longer valid.