Shrub: red dogwood (Cornus) (Caldecott OX14)

Cornus with dark red stems, currently about 1 m high. It grows fast, up to a couple of metres, and can be pruned right back (even to ground level if you want) in late spring to give fresh crimson stems that look great in winter. It has creamy flowers in May.
It's in a pot that I want to keep, so I'll give it to you in a bag; plant it in a pot or the ground fairly soon, give it a good watering and cut it back a bit and it'll be fine.