It is a Leptospermum Petersonii, AKA Lemon Scented Tea Tree ... here's the blurb from wiki :
Leptospermum petersonii, lemon-scented teatree is a tall shrub to small tree, growing to a maximum of 5 metres which is cultivated as an ornamental and for essential oils. It naturally occurs near sclerophyll forest or rainforest, on sandy or rocky escarpments, on the east coast of Australia.
I was drawn to the bark on it primarily, but have been informed that the leaves will reduce nicely and they take to bonsai very well ...

Anyway, here it is :
