The common name “Elephant Ear” describes a group of tropical plants prized for their large, dramatic foliage, but it is not a single species. This term is broadly applied to several different genera within the Arum family (Araceae). These plants, all sharing the characteristic heart- or arrow-shaped leaves, are primarily members of the genera Colocasia, Alocasia, and Xanthosoma. Understanding the distinctions between these genera is important not just for identification, but also for proper cultivation, as their care needs differ significantly.
The Plant Most Often Called Elephant Ear
The plant most traditionally and globally recognized by the common name “Elephant Ear” is Colocasia esculenta. This species is native to tropical Asia and is arguably the oldest cultivated plant in the Arum family. It is known by numerous common names worldwide, including Taro, Eddoe, and Dasheen, reflecting its long history as a staple food crop. Colocasia grows from a starchy underground corm (the edible part) and produces large, heart-shaped leaves. The leaves have a typically matte or velvety texture and are known for their ability to repel water, causing droplets to bead and roll off the surface. This genus generally prefers consistently moist to boggy conditions.
The Two Major Look-Alikes
The two other genera frequently sold and grown under the “Elephant Ear” moniker are Alocasia and Xanthosoma. Both share the family characteristics of large, often sagittate (arrow-shaped) leaves and growth from corms, but they originate from different regions. Alocasia is native to tropical southern Asia and the Pacific Islands, while Xanthosoma originates from tropical America. Alocasia plants, sometimes called “African Mask Plants,” often feature leaves that are more glossy and have a defined, pointed edge. Xanthosoma species, known in some regions as Malanga or Cocoyam, are typically large, robust plants with leaves that are distinctly arrow-shaped and possess a smooth, sometimes waxy upper surface.
Physical Characteristics That Differentiate Them
The most reliable way to distinguish between these three plants involves observing three specific physical characteristics: leaf orientation, petiole attachment, and leaf shape.
Leaf Orientation
Colocasia leaves are known for their cascading habit, with the leaf tips pointing noticeably downward toward the ground. In contrast, Alocasia leaves generally point their tips upward or horizontally outward. Xanthosoma is more variable, usually holding its leaves horizontally or with a slight downward angle, but rarely with the dramatic droop of Colocasia.
Petiole Attachment
The second major distinction is found where the petiole, or leaf stem, attaches to the leaf blade. Colocasia is characterized by peltate leaves, meaning the petiole attaches near the center of the leaf, away from the edge or notch. The stem appears to pierce the leaf. Both Alocasia and Xanthosoma leaves are non-peltate, meaning the petiole attaches directly at the edge, specifically at the “V” notch (sinus) of the leaf.
Leaf Shape
Finally, the leaf shape helps separate Alocasia from Xanthosoma. Xanthosoma leaves are typically more elongated and distinctly arrow-shaped with a pronounced, open notch, while Alocasia leaves often have more defined veins and sharper edges.
Essential Care and Safety Considerations
All three genera of “Elephant Ear” plants are tropical and share general requirements for warmth, moisture, and light. They prefer warm temperatures and generally thrive in environments with high humidity. While Colocasia is highly tolerant of consistently wet, even boggy soil conditions, Alocasia and Xanthosoma generally require well-drained soil that remains consistently moist but not saturated.
All parts of these plants—the leaves, stems, and corms—contain needle-like structures called raphides, which are crystals of calcium oxalate. When ingested raw, these crystals cause an immediate and localized inflammatory response, leading to irritation, a burning sensation in the mouth, swelling, and difficulty swallowing. While the corms of many Colocasia and some Xanthosoma species are traditional food sources, they must be thoroughly cooked or processed to neutralize the calcium oxalate content. Therefore, all ornamental varieties should be handled with care and placed safely away from pets and small children.