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..
Herbs or shrubs (rarely trees), with a watery sap, alternate or very rarely opposite, simple or palmately compound leaves and axillary or terminal, solitary or racemose, regular or irregular, mostly perfect flowers. Sepals 4-8. Petals 4 (rarely none), sessile or clawed. Receptacle elongated or short. Stamens 6-∞, not tetradynamous, inserted on the receptacle; anthers oblong. Ovary sessile or stipitate; style generally short; ovules ∞, borne on parietal placentae. Fruit a capsule or berry. Seeds mainly reniform in our species; endosperm none; embryo generally coiled.
A family of about 35 genera and 450 species, mostly of warm regions.
Pod long-stipitate on its pedicel; stamens 4-6.
Pod linear-elongated; petals generally clawed.
Pod short, rhomboid; petals sessile.
Pod nearly or quite sessile on its pedicel; stamens more than 6.