In the United Kingdom, Ireland, and most of the english speaking countries it is referred to as Curry Plant because of its strong fragrance, close to curry. Aromatherapy books often refers to it
In United States and Canada the scientific name Helichrysum Italicum is used the most.
There are many other names for it, we listed most here. In any case, you may always use the name Immortelle to speak about this wonderful shrub