An herbaceous perennial, Xanthosoma sagittifolium has a corm or main underground stem in the form of a rhizome from which swollen secondary shoots, or cormels, sprout. The spadix (a spike of minute flowers) is cylindrical, with female flowers on the lower portion, male flowers on the upper portion and sterile flowers in the middle portion. The growth cycle lasts from 9 to 11 months: during the first six months the corms and leaves develop; in the last four months, the foliage remains stable and, when it begins to dry, the plants are ready for the cormels to be harvested. Xanthosoma is native to tropical America. The leaves are edible, but they (and all parts of the plant) contain needle-like crystals of calcium oxalate which are a skin irritant, so they must be cooked first.