Dioon — 13 species

Dioon is a genus of ancient cycads native to Mexico and Central America, producing stiff, palm-like fronds from a slow-growing central trunk. They demand bright, direct sun — ideally within a foot of a south-facing window — and very well-draining soil that is allowed to dry out fully between waterings, as they are highly sensitive to overwatering and root rot. All Dioon species are toxic to cats and dogs; every part of the plant, especially the seeds, contains cycasin, a potent toxin that can cause liver failure.