Chia seed black is a species of flowering plant in the mint family, Lamiaceae, native to central and southern Mexico and Guatemala. The sixteenth-century Codex Mendoza provides evidence that it was cultivated by the Aztec in pre-Columbian times and economic historians say it may have been as important as maize as a food crop. It was given as an annual tribute by the people to the rulers in 21 of the 38 Aztec provincial states.
Chia seeds are grown and commonly used as food in several countries of western South America, western Mexico, and the Southwestern United States.
Chia is an annual herb growing up to 1.75 metres (5.7 feet) tall, with opposite leaves that are 4–8 cm (1.6–3.1 in) long and 3–5 cm (1.2–2.0 in) wide. Its flowers are purple or white and are produced in numerous clusters in a spike at the end of each stem. Chia is hardy from USDA Zones 9–12. Many plants cultivated as S. hispanica are in fact Salvia lavandulifolia.
Typically, chia seeds are small ovals with a diameter of approximately 1 mm (0.039 in). They are mottle-colored with brown, gray, black, and white. The seeds are hydrophilic, absorbing up to 12 times their weight in liquid when soaked. While soaking, the seeds develop a mucilaginous coating that gives chia-based beverages a distinctive gel texture.