Colocasia — 21 species

Colocasia — the true elephant ears — are bold, tropical aroids grown for their enormous, heart-shaped leaves in colours ranging from lime green to near-black, with cultivars such as 'Black Magic', 'Mojito', and 'Illustris' being popular statement specimens. They thrive in bright to full sun with consistently moist to wet soil; container-grown plants may need watering daily in warm weather. The ASPCA confirms the entire genus is toxic to cats, dogs, and horses: insoluble calcium oxalate crystals cause immediate oral irritation, drooling, and vomiting on ingestion, so keep well away from pets.