This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Humus-plants or saprophytes, with mostly simple, leafless bracted scapes, and solitary or clustered perfect regular flowers. Calyx 2-6-parted, free from the ovary; sepals erect, connate at the base, imbricated, deciduous. Corolla gamopetalous or polypetalous (wanting in the California Allotropa); lobes or petals 3-6. Stamens 6-12, hypogynous; filaments distinct, or united at base; anthers 2-celled or confluently 1-celled, attached to the filaments by their backs or bases; pollen-grains simple. Disk obsolete or 8-12-lobed. Ovary superior, 4-6-lobed, 1-6-celled; style short or elongated; stigma capitate or peltate; ovules numerous, anatropous. Capsule 4-6-lobed, or terete, 1-6-celled, loculicidally 4-6-valved, many seeded. Seeds minute, the testa reticulated.
About 9 genera and 12 species, mostly of the northern hemisphere, most abundant in North America.
Corolla gamopetalous, persistent.
Corolla globose-ovoid; anthers 2-awned.
Corolla campanulate; anthers awnless.
Corolla polypetalous, deciduous.