This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", 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 trailing, herbaceous vines, usually with tendrils. Leaves alternate, petioled, generally palmately lobed or dissected. Flowers solitary or racemose, monoecious or dioecious. Calyx-tube adnate to the ovary, its limb campanulate or tubular, usually 5-lobed, the lobes imbricated. Petals usually 5, inserted on the limb of the calyx, separate, or united into a gamopetalous corolla. Stamens mostly 3 (sometimes 1), 2 of them with 2-celled anthers, the other with a 1-celled anther; filaments short, often somewhat monadelphous. Ovary 1-3-celled; style terminal, simple or lobed; ovules few or numerous, anatropous. Fruit a pepo, indehiscent, or rarely dehiscent at the summit, or bursting irregularly; or sometimes dry and membranous Seeds usually flat; endosperm none.
About 90 genera and 700 species, mainly natives of tropical regions, a few in the temperate zones Flowers large, yellow; prostrate vine.
Flowers small, white or greenish; climbing vines. Fruit glabrous; seeds numerous, horizontal.
Fruit prickly; seeds 1 or few, erect or pendulous.
Fruit dehiscent at the apex or bursting irregularly; several-seeded. Leaves 3-7-lobed; anthers 3.
Leaves digitately compound; anther 1.
Fruit indehiscent, 1-seeded.