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..
Low tufted shrubs, or perennial scapose herbs, with alternate or basal simple exstipulate leaves, and small white pink or purple gamopetalous or polypetalous perfect and regular flowers, solitary in the axils, or racemose at the summit of scapes. Calyx 5-parted, persistent; sepals imbricated in the bud. Corolla 5-lobed, 5-cleft, or 5-parted, deciduous. Stamens 5, inserted on the throat of the corolla and alternate with its lobes, or connate, sometimes with as many alternating staminodia; anther-sacs longitudinally or transversely dehiscent; pollen-grains simple. Disk none. Ovary free from the calyx, superior, 3-celled; style mostly stout, persistent; stigma 3-lobed; ovules few or numerous in the cavities, ana-tropous or amphitropous. Capsule 3-celled, loculicidally 3-valved. Seeds minute, the testa loose or close; endosperm fleshy; embryo terete; cotyledons short; radicle elongated.
Six genera and about 8 species, natives of the northern hemisphere.
Low tufted evergreen shrubs; corolla gamopetalous.
Trailing shrub; flowers solitary, sessile.
Tall scapose perennial herb; flowers spicate-racemose; petals separate.