fruit of Persea americana of the family Lauraceae, a tree native to the Western Hemisphere from Mexico south to the Andean regions. The tree, tall or spreading, has leaves elliptic to egg-shaped in form and 100–300 mm (4–12 inches) in length. The small, greenish flowers, borne in dense racemes, are devoid of petals and have six perianth lobes, nine stamens arranged in three series, and a one-celled ovary. The fruit is exceedingly variable in shape, size, and colour, with certain Mexican races no larger than hen's eggs and those of other races sometimes 1 to 2 kg (2 to 4 pounds) in weight. The form varies from round to pear-shaped with a long, slender neck, and the colour ranges from green to dark purple. The single large seed, with two cotyledons, is round to conical. The fruit's outer skin is sometimes no thicker than that of an apple and sometimes is coarse and woody in texture. It protects the greenish or yellowish flesh, buttery in consistency and with a rich, nutty flavour. In some varieties the flesh contains as much as 25 percent of unsaturated oil. It is often eaten in salads, whence the name salad fruit. Mashed avocado is the principal ingredient of guacamole, a characteristic sauce in Mexican cuisine. Avocados provide thiamine, riboflavin, and vitamin A.