Willamette hops are a hybrid of the English Fuggle hop that were released by the USDA in 1976 and are named for the Willamette Valley where the majority of Oregon hops are grown.  The valley is on the 45th parallel which is closer to that 48th parallel that is noted as the place where hops grow the best because of the distinct seasons and the length of the day in the summer season.  They are a popular American flavor hop variety known for their earthy aroma and pleasant taste in a finished beer.