Practical information to identify and manage non-native, invasive plants
The Quiet Invasion:A Guide to Invasive Plants of the Galveston Bay Area
Colocasia esculenta
| USDA Symbol: | COES |
| ITIS TSN: | 42549 |
| Presence: | Current Invaders |
| Habitat: | Terrestrial |
| Native Range: | South Asia and India; common in Africa |
Toxic Characteristics
Produces needle-like crystals in all plant parts that cause irritation if ingested raw. Sap can irritate sensitive skin.Geographic Distribution
Occurs in the southeastern U.S. west to southeast Texas, as well as Puerto Rico and Hawaii. Common in local residential and urban areas; naturalized along banks of bayous and lakes within the Lower Galveston Bay watershed.Introduction Pathways
Introduced to the United States in 1910 as a substitute crop for potatoes. Later cultivated as an ornamental. Numerous varieties continue to be sold.Specific Primary Habitats
Needs soil that is moist to wet, mildly acidic, and rich in organic material. Found spreading along wetland fringes as well as stream, ditch, canal, and lake banks.Identifying Characteristics
Leaves reach 2 - 3 feet in length and are heart or arrowhead-shaped, green to bluish-black between light-colored primary veins, all emerging basally from an underground stem, or corm. Petioles attach to the middle of the underside of leaf and are green to red, often violet, and can reach 4 feet. The corm is a starchy root reaching 6 inches in diameter and weighing up to 6 lbs. Flowers occur at the apex of a fingerlike flower stalk. Seeds are 2 - 5 per berry and are generally rare.Reproduction Characteristics
Reproduces primarily vegetatively, via culm fragmentation and budding at the base of the plant. Disturbance greatly encourages its spread.Growth Characteristics
Elephant ear is a fast grower in the presence of warm, wet conditions. Will rapidly spread over an area with appropriate wet soil.Ecological, Economic, or Social Impact
Taro invades wetland areas and colonizes lake banks, forming dense growth. Outcompetes native species, thus altering natural habitat and ecosystem processes; reduces biodiversity.Suggested Control Methods
1% solutions of 2,4-D, triclopyr, or glyphosate have provided effective control within 6 weeks of application. In mechanical removal, all care must be taken to keep the plant intact, as remaining fragments will readily germinate.|
Native Species Alternatives
Below is a list of alternative plants that are native to the area:
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Lists
This species belongs to the following lists:
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Images
To view a larger version of an image, click on the thumbnail. A field of cultivated coco yam in Hawaii. Photo courtesy of Charles T. Bryson, USDA Agricultural Research Service, www.forestryimages.org; Image Number 1197043. |
 Close-up of the coco yam in cultivation. Photo courtesy of Charles T. Bryson, USDA Agricultural Research Service, www.forestryimages.org; Image Number 1197044. |
 Naturalized elephant ear along the banks of Armand Bayou in Harris County, Texas. Photo courtesy of Brenda Weiser, Environmental Institute of Houston, University of Houston-Clear Lake. |