What are some single sexed plants native to England.?

Question

This is for a science assignment at college so some plants that can be found throughout the U.K would be good as I have to coolect them. Thanks.

Answer 1

It's a bit more complex than that, but the term you are looking for is "dioecious". See source list for more detail.
The holly is perhaps the most familiar in Britain. The second source on the list gives more such plants, but it's a USA list, unfortunately.

Answer 2

Holly is the obvious, Skimmia is another, its common but I doubt that its native.