Gwen

Gwen is a Guatemalan-type hybrid discovered in the 1980s by Gwen Zabicki on a tree in her Southern California orchard, developed just as Hass was taking over the world market. It is widely rated among the very best-tasting avocados, with some growers preferring it even to Hass, yet it never caught on commercially because its skin stays green rather than turning black when ripe. A parent of the later Lamb Hass, it remains a favorite for home orchards.