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..
Climbing or twining woody or herbaceous vines, with alternate entire or lobed leaves, no stipules, and small dioecious panicled racemose or cymose flowers. Sepals 4-12. Petals 6, imbricated in 2 rows, sometimes fewer, or none. Stamens about the same number as the petals. Carpels 3-00 (generally 6), 1-ovuled, separate; styles commonly incurved. Fruit drupaceous, often oblique. Endosperm little. Embryo long, curved.
About 55 genera and 150 species, mainly of tropical distribution, a few extending into the temperate zones.
Petals none; anthers 2-celled.
Petals present; anthers 4-celled or 4-lobed.
Stamens 6; drupe red.
Stamens 12-many; drupe black.