Crocosmia masonorum Recent discussion on it in this thread http://www.growsonyou.com/question/show/256737
Title is My wife

If you only have a small patch of soil, Rachael, you may well regret introducing this thug.

there are others which are less invasive, look on google at the various crocosmias available you will see dozens of hybrids which are beautiful and do not cause problems in small places.

Thank you all for the advice and name of plant. I will check out the options. It looks nice in my friends garden but I must admit it is a large space and he is not a gardener. so he just happy for it to go mad.

If you type Crocosmias into the search box you'll find a great many pics of different modern varieties that are more attractive than the old fashioned one your friend has.