"Itoh" peonies are all the rage this year - they are a range of hybrids between herbaceous and tree peonies. They die down to some small branch like structures just above ground level so I suppose that they are technically "sub-shrubs".
We visited our friend Stephen Ryan who runs "Dicksonia Rare Plants Nursery" on Mt Macedon in July and bought one from him called "Pastel Splendour" which is flowering now (still in its pot!)
cheers
fermi
