This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", 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..
Parasitic green shrubs or herbs, containing chlorophyll, growing on woody plants and absorbing food from their sap through specialized roots called haus-toria (a few tropical species terrestrial). Leaves in the following genera opposite, in Razoumofskya reduced to opposite scales. Flowers regular, terminal or axillary, clustered or solitary, dioecious or monoecious, and perianth simple, or in some exotic genera perfect, and with perianth of both calyx and corolla. Calyx-tube adnate to the ovary, its limb entire, toothed or lobed. Stamens 2-6; anthers 2-celled or confluently 1-celled. Ovary solitary, erect; style simple or none; stigma terminal, undivided, obtuse. Fruit a berry. Seed solitary, its testa indistinguishable from the endosperm, which is usually copious and fleshy.
About 21 genera and 500 species, widely distributed; most abundant in tropical regions.
Leaves scale-like, united at the base; anthers 1-celled; berry peduncled.
Leaves thick, flat; anthers 2-celled; berry sessile.