English name: Dioon
Dioon, genus of 10 species of cycads in the family Zamiaceae, native to Mexico and Central America. The spiny-leaved slow-growing giant dioon (Dioon spinulosum) may attain a height of 15 metres (about 50 feet). It is a popular houseplant and is grown outdoors as an ornamental in warmer climates. Starch like that of arrowroot is obtained from the seeds of the chestnut dioon (D. edule).