Avocado (Persea americana) is one of the earliest fruits consumed in Mesoamerica and one of the first trees domesticated in the Neotropics. The word avocado derives from the language spoken by the Aztecs (Nahuatl) who called the tree ahoacaquahuitl and its fruit ahuacatl; the Spanish called it aguacate.
The oldest evidence for avocado consumption dates back almost 10,000 years in Puebla state of central Mexico, at the site of Coxcatlan. There, and in other cave environments in the Tehuacan and Oaxaca valleys, archaeologists found that over time, avocado seeds grew larger. Based on that, the avocado is considered to have been domesticated in the region by between 4000-2800 BC.
The Persea genus has twelve species, most of which produce inedible fruits: P. americana is the best known of the edible species. In its natural habitat, P. americana grows to between 10-12 meters (33-40 feet) high, and it has lateral roots; smooth leathery, deep green leaves; and symmetrical yellow-green flowers. The fruits are variously shaped, from pear-shaped through oval to globular or elliptic-oblong. The peel color of the ripe fruit varies from green to dark purple to black.
The wild progenitor of all three varieties was a polymorphic tree species that spanned a broad geographical area from the eastern and central highlands of Mexico through Guatemala to the Pacific coast of Central America. The avocado should really be considered as semi-domesticated: Mesoamericans didn't construct orchards but rather brought a few wild trees into residential garden plots and tended them there.
Three varieties of avocado were created separately in three different locations in Central America. They were recognized and reported in surviving Mesoamerican codexes, with the most detail appearing in the Aztec Florentine Codex. Some scholars believe these varieties of avocados were all created in the 16th century: but the evidence is inconclusive at best.
- Mexican avocados (P. americana var. drymifolia, called the aoacatl in the Aztec language), originated in central Mexico and are adapted to the tropical highlands, with relatively good tolerance to cold and small fruits that are covered by a thin, purple-black skin.
- Guatemalan avocados, (P. americana var. guatemalensis, quilaoacatl) are from southern Mexico or Guatemala. They are similar in shape and size to the Mexican but have a more ovoid and lighter-colored seed. Guatemalan avocados are adapted to medium elevations in the tropics, are somewhat cold-tolerant, and have a thick, tough skin.
- West Indian avocados (P. americana var. americana, tlacacolaocatl), despite their name, are not from the West Indies at all, but rather were developed in the Maya lowlands of central America. They are the largest of the avocado varieties and are adapted to lowland humid tropics and tolerant of high levels of salt and chlorosis (plant nutrient deficiencies). The West Indian avocado fruit is round to pear shape, has a smooth easy-to-peel light green skin and abundant flesh with a slightly sweet taste.
There are about 30 main cultivars (and many others) of avocados in our modern markets, of which the best known include the Anaheim and Bacon (which are derived almost entirely from Guatemalan avocados); Fuerte (from Mexican avocados); and Hass and Zutano (which are hybrids of Mexican and Guatemalan). Hass has the highest volume of production and Mexico is the major producer of exported avocados, nearly 34% of the entire global market. The major importer is the United States.
Modern health measures suggest that eaten fresh, avocados are a rich source of soluble B vitamins, and of about 20 other essential vitamins and minerals. The Florentine codex reported avocados are good for a variety of ailments including dandruff, scabies, and headaches.
The few surviving books (codices) of the Maya and Aztec cultures, as well as oral histories from their descendants, indicate that avocados held a spiritual significance in some Mesoamerican cultures. The fourteenth month in the classic Mayan calendar is represented by the avocado glyph, pronounced K'ank'in. Avocados are part of the name glyph of the classic Maya city of Pusilhá in Belize, known as the "Kingdom of the Avocado". Avocado trees are illustrated on the Maya ruler Pacal's sarcophagus at Palenque.
According to Aztec myth, since avocados are shaped like testicles (the word ahuacatl also means "testicle"), they can transfer strength to its consumers. Ahuacatlan is an Aztec city whose name means "place where the avocado abounds".
This glossary entry is a part of the About.com guide to Plant Domestication, and the Dictionary of Archaeology.
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