teosinte, any of four species of tall, stout grasses in the genus Zea of the family Poaceae. Teosintes are native to Mexico, Guatemala, Honduras, and Nicaragua. Domesticated corn, or maize (Zea mays mays), was derived from the Balsas teosinte (Z. mays parviglumis) of southern Mexico in pre-Columbian times more than 6,000 years ago.
Teosintes are solitary (single-stalked) annuals or spreading perennials. Annual species strongly resemble domesticated corn in their large terminal plumelike male inflorescences (the tassels). However, they differ in their small 5–12-seeded female ears, which are hidden in clusters in the leaf axils. Teosintes have a high resistance to both viral and fungal diseases of corn as well as corn insect pests.