The Hass avocado is a variety of avocado with dark green, bumpy skin. It was first grown and sold by the American horticulturist Rudolph Hass, who also gave it his name. The Hass is one of the most commercially popular avocado cultivars and accounts for more than 80 percent of the crop in the United States. This is due to its taste, size, shelf-life, high growing yield and in some areas, year-round harvesting. The fruit has a mass of 200 to 300 grams (8 to 10 ounces) and, when ripe, its skin becomes a dark purplish-black that yields to gentle pressure. The centre part of the inner fruit then becomes white-green. This picture shows a whole and a halved Hass avocado, cultivated in Colombia. The photograph was focus-stacked from 12 separate images.Photograph credit: Ivar Leidus