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.
(As in the case of cornfields, hills, waste places, walls, etc, the plants that are included here may be found in some other habitats occasionally, since the roadside and the hedge are of modern origin. But the latter are pre-eminently the stations for a number of plants that are especially fond of a hedge-bottom or a bank, and they afford a place of refuge for such species from the attacks of cattle. The shade-lovers also that have survived the cutting down or disappearance of the woods and forests are able to flourish in the hedge.)