Wild Taro, Colocasia esculenta, is a non-native plant that can displace native stream bank and mid-stream plants by over-shading and by emitting toxins from its roots.
It is invading the Cahaba River’s banks and shoals, threatening the native American water willow, Justicia americana, and the Cahaba lily, Hymenocallis coronaria, which provide spawning habitats for a large number of aquatic species.
Thank you to Samford’s Department of Geography and Sociology for their partnership in creating this reporting system.
Cahaba River Society field director Randy Haddock paddles a canoe beside wild taro plants growing along the banks of the Cahaba River.
Wild Taro has been grown worldwide as a food source for thousands of years and, more recently, as a large ornamental landscape plant.
In the U.S., Wild Taro has escaped into urban rivers and streams, replacing native plant species.
Invasive wild taro growing in Cahaba Lily habitat.
Cahaba River Society is tracking sightings of taro in and around the Cahaba River, so let us know if you see plants.
Thanks to a partnership with Samford’s Department of Geography and Sociology, you can report sightings quickly and easily using an app. Click below to report a sighting.
Wild Taro leaf
Native Arrowhead leaf
Arrowhead leaf is a native plant that has lovely heart-shaped leaves and is beneficial to be grown in the southeast.
The primary feature that distinguishes Wild Taro from our native Southern arrowhead, Sagittaria australis, which grows in the same habitat, is the insertion point, where the stem (petiole) attaches to the leaf blade. On Wild Taro, the insertion point is near the middle of the leaf blade (above left). On arrowhead, the insertion point is at the notch or vertex of the cleft of the leaf blade (above right).
There are many colorful varieties. Wild Taro can grow to be six feet tall and outgrow its planting space quickly.
While any species of taro may be invasive, the Wild Taro with solid green leaves (pictured above left), is particularly aggressive.
“While this widely-used landscaping plant might look interesting and attractive, it is actually creating the early stages of an ecological disaster.”
– Dr. Randy Haddock, Field Director, Cahaba River Society
Wild Taro has moved into the waters of the southern two-thirds of Alabama. It takes root in wet ditches, along the margins of ponds and lakes, on the banks and shoals of rivers and creeks, in swamps and marshes, and in hardwood floodplain forests.
The Coosa River and Black Warrior Rivers are already badly degraded by Wild Taro in some places.
We must keep this destructive plant from becoming established in the Cahaba River as well.
Wild Taro spreads rapidly by long rhizomes and corms, both forms of underground stems. A parent-plant sends out yards-long rhizomes that quickly generate new plants.
In rivers and streams, these new plants break off easily and establish colonies downstream, increasing the challenge of removing them.
Often homeowners thin Wild Taro out of planting beds and deposit it onto street curbs, where it washes into storm drains and is carried to local rivers. Unless disposal is controlled, Wild Taro can become invasive in rivers and displace native plants.
Young wild taro plants sprout in the Cahaba River.
There are a few things that you can do to help stop taro from taking over the Cahaba River:
Know what wild taro looks like.
Don’t allow corms, roots, rhizomes (underground stems that produce shoots and roots) or seeds to wash into storm drains or local waterways.
When disposing of taro, always bag the plants for disposal in a landfill.
When removing Wild Taro, wear gloves and protective clothing. Plant sap may ruin clothing and irritate skin as it contains large amounts of oxalic acid.
Oxalic acid seeps from a cut Wild Taro stem. This sticky substance can stain clothes and irritate skin.
Contact Cahaba River Society if you find Wild Taro in the Cahaba River or any of its tributaries, such as Shades Creek.
Contact Cahaba River Society if you would like to volunteer to help remove taro.
Spread the word! Many people do not know that this common landscaping plant can be such a hazard to our environment. Tell relatives, friends, and neighbors.
Invite us to come spread the word! Cahaba River Society has developed a presentation about Wild Taro for landscape and gardening professionals and enthusiasts. Call 205-322-5326 or email to request a presentation to your garden club, professional association, or other organization that can help control the spread of wild taro.
Never place loose taro plants at the curb for trash collection. Plant parts can wash into storm drains and reach waterways, allowing them to spread.
Cahaba River Society works with partner groups and volunteers to remove taro from sensitive Cahaba lily habitat.
Cahaba River Society and the Birmingham Botanical Gardens have worked together to produce a brochure that can help bring information about invasive taro to landscape and garden professionals and enthusiasts.
Copies of the brochure are available for free to the public. Contact Cahaba River Society by calling 205-322-5326 or emailing to request a copy, or download a printable version online.
Through a partnership with Samford’s Department of Geography and Sociology, Cahaba River Society has developed a reporting system for taro sightings and a map of known locations of invasive taro. View the map below to see locations and click for details.