You could have trouble finding the plant you want under nemorosa, superba or sylvestris. They are probably most commonly referred to as superba in Australia I think. These photos above is of ‘Rubin’ and ’Blue Hills’ (‘Blauhugel’). The banner (photo up the top) is of a plant I received as seed from the Hardy Plant Society in the UK as nemorosa Midsummer. I think it is really regeliana these days. It grows quite large – perhaps a metre by a metre.