Elephant's ear (Alocasia spp.) includes 79 different species of showy, large-leaved, tropical plants, some with colorful leaves. It's appearance varies depending on the species and there is a wide variety of leaf sizes, coloring and variations. All parts of these plants contain sharp, needle-like calcium oxalate crystals. When chewed, the crystals can penetrate the tongue, throat, and inside of the mouth to cause severe irritation.