Distinguishing Between Alocasia, Colocasia, and other Elephant Ears

Alocasia california

Elephant ear varieties are popular foliage plants in the US that though toxic, are a starchy food for hundreds of millions of people worldwide. As Araceae family members, they include the genera Alocasia, Colocasia, Xanthosoma, and Caladiums. Some grow along the banks of ponds, rivers, and streams while others prefer uplands. Their corms are marketed as bulbs and potted up for sale as landscape material and houseplants. Select varieties are cooked rendering harmless the calcium oxalate toxin in their tissue that’s also found in rhubarb, dieffenbachia, and philodendrons.

Colocasia typically grows well in swampy areas along river banks, while Alocasia, Xanthosoma, and Caladiums tend to instead prefer moist, well-draining organic soil. They spread via rhizomes that form corms giving rise to additional stems.

There is a great deal of literature on distinguishing between Alocasia and Colocasia. The petiole or leaf stem of Alocasia is connected at the leaf notch which causes the leaf to point upward whereas the petiole is farther down from the notch in Colocasia causing the leaf to droop. Xanthosomas typically have arrow-shaped leaves that are waxy and heavily veined. Caladiums are much smaller with leaves that appear as fragile as tissue paper that point downwards. Microscopic differences in the flower structure are the most accurate method of distinguishing between varieties that are otherwise widely misnamed.

The common name ‘elephant ear’ used in the USA is interchangeable with their food variety names including taro (Colocasia esculenta) in Asia and the South Pacific, Eddoes (Colocasia antiquorum) in the West Indies and Brazil. At the same time, Malanga or Cocoyam (Xanthosoma sagittifolium) is prominent in diets in the Americas and Africa. Adding to the confusion, “Colocasia antiquorum has been subsumed into Colocasia esculenta and is now listed as a variety of that species,” according to San Marcos Growers. Both Colocasia esculenta and Xanthosoma sagittifolium are considered invasive species in Florida. “No matter what cultivar you select, never plant elephant ears in or near a natural waterway; many spread rampantly and become a problem,” according to the University of Florida.

“It is an ancient crop in Asia, being introduced into Japan more than 2500 years ago,” wrote the Encyclopedia of Food Sciences and Nutrition regarding taro. “It is considered a food staple for more than 500 million people in the regions of Asia, Africa, Central America, and the Pacific Islands,” wrote Advances in Food and Nutrition Research regarding taro. “In the southern Mediterranean, it is consumed more than potatoes.”

“Cocoyam (Xanthosoma sagittifolium) is among the world’s six most important root and tuber crops,” according to Food Science & Nutrition. “However, it remains an underexploited food resource. The challenge of underutilization is exacerbated by the existing confusion in taxonomy and nomenclature which limits researchers in exploiting data from one area of indigene to another.” Notwithstanding the confusion of distinguishing between them, these corms are the potato of the tropical world. “Of all the vegetables, malanga causes the most confusion,” according to The Spruce Eats. “It looks so much like the related taro and eddo corms that a number of common names are applied to this group and they’re often used interchangeably.” The best authorities on elephant ear dishes may be at your local farmers’ market, ethnic food store, and restaurant.

The plant trade markets a large number of elephant ears with multiple synonyms for the same species. The Plant List is a working list of all known plant species that identifies the species per variety as 79 Alocasia, 73 Xanthosoma, 16 Colocasia, and 12 Caladiums. The heavily marketed caladiums with their diverse color patterns are sold under 179 synonyms.

Alocasia amazonica ‘Bambino’ is a jewel (dwarf) variety reaching 12” in height with white venation on the thick dark green arrow-shaped leaves. They grow best in well-draining soil and are a relatively easy-care houseplant preferring bright indirect light.

Alocasia amazonica ‘Bambino’

Alocasia Gagaena California is a fast-growing variety reaching 4’ maximum height with light green leaves and deep venation that lends a crinkled look to the large upward-pointing leaves. They are considered among the most cold-hardy of varieties grown outdoors.

Alocasia Gagaena California

Alocasia Lauterbachiana, the purple sword elephant ear grows to 4′ maximum height with long narrow, sword-like leaves. Lauterbachiana prefers well-draining soil and bright indoor light. Keep away from drafts as they are quite cold-sensitive and prefer temperatures above 60 degrees.

Alocasia Lauterbachiana

Alocasia Maharani is also known as the gray dragon is a jewel variety with a 14″ maximum height. They like bright indirect light and moist though well-draining soil. Keep Maharani at temperatures above 60 degrees.

Alocasia Maharani

Alocasia Odora is also known as Night Fragrant Lily exhibiting upturned leaves and peach-colored fragrant blooms in Spring and Summer. They prefer full to partial shade growing 4-6’ in height in moist, rich organic soil.

Alocasia Odora

Alocasia Regal Shield grows to a 5′ maximum height with thick, dark green leaves and burgundy undersides. They don’t like wet feet, but moist rich organic well-draining soil and filtered light outdoors and indirect light indoors. They enjoy humidity and do best in temperatures above 65F degrees.

Alocasia Regal Shield

Alocasia Yucatan Princess has dark green leathery foliage with a hint of purple on red stalks reaching 6’ maximum height. Yucatan Princess is a mutation of Alocasia sarawakensis thus often referred to as Alocasia Sarawakensis Yucatan Princess. They prefer moist, well-drained soil and indirect or filtered light.

Alocasia Yucatan Princess

Alocasia Reginula, also known as Black Velvet Alocasia has a rich green nearly black color with silver-white venation reaching a maximum height of 3′, but are typically much smaller and suited for terrariums. They prefer temperatures above 60 degrees in well-draining soil with indirect sunlight.

Alocasia Reginula

Syngonium podophyllum is a vining aroid with arrow-shaped leaves that are often confused with caladiums. Unlike caladiums and other aroids discussed here, Syngonium spreads by aerial or adventitious roots and can be propagated by stem and leaf node cuttings. Syngonium prefers well-draining, aerated soil, indirect light, high humidity, and temperatures above 60 degrees.

Syngonium podophyllum

Caladiums grow to a maximum height of 2’ and are widely propagated and sold as bulbs (actually are corms) and as potted plants. Most color varieties prefer indirect or filtered light and do best in well-draining soil. They are not frost hardy resulting in dieback as Fall temperatures drop below 60 degrees.

Caladiums

Earth Works Garden Center/Plant Nursery, Landscaping, and Lawn Care divisions that make available and care for a wide selection of genera Alocasia, Colocasia, Xanthosoma, Caladiums, and Syngonium. A reminder that all Aroids should be considered toxic requiring caution around children and pets.

For comprehensive solutions to your specific lawn, garden, and landscaping needs, contact Earth Works of Jacksonville online and at 904-996-0712.
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