What will grow in clay soil?

Hi, I'm a brand new gardener and quite frankly don't know the first thing!

The soil in my garden is extremely clay like, I've never seen anything like it.  I planted lavender and burburis last year and they're all dead.

I'd like to plant some evergreen perennials and was wondering if anyone knows what will grow in the damp clay conditions?  I'm looking for something bush like to create a boundary.

Thanks in advance!