This section is from the book "British Wild Flowers - In Their Natural Haunts Vol5-6", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
The habitat of this plant is hedges and copses. The habit is twining, climbing, and the plant is rough. The root-stock is stout, branched. The stem is tall, almost prickly, tough. The branchlets are hairless. The leaves are stalked, heart-shaped, opposite, smooth above, rough below, 3-5-lobed, the lobes acutely toothed, egg-shaped, toothed, the uppermost egg-shaped. The male flowers are loosely panicled, the female on curved flower-stalks, in fruit yellow, egg-shaped, globular, with egg-shaped scales, the scales rounded, glandular, resinous, like the fruit and bracteoles. The fruit is dry, with pendulous seeds. The plant is climbing, revolving to the right, a revolution taking- 2 hours. It is 4-12 ft. high, flowering from July to September, and is a herbaceous perennial.