In Sauternes and Barsac, this is the grape susceptible to "noble rot". Some say its aroma is remintscent of lanolin, but as pure lanolin is virtually odorless, the comparison hardly conveys the Semilllon's distincitve bouquet.  For dry wine, this grape is at its best in Australia, particularly the Hunter Valley, where its lime fruit takes to oak, whereas bottle-aged Semillon can be sublime after several decades.

Info : The Sotheby's Wine Encyclopedia 4th Ed by Tom Stevenson