COLLEGE STATION — A ground-covering plant has shown up in several Houston yards and scientists at Texas A&M University warn that the exotic species though attractive — will make itself at home and not leave.
Efforts to control this trailing weed, a South American plant called Lysianthes asarifolia, have failed in one trial yard in the Hunter Creek Village area, despite multiple sprayings of the maximum amounts of several herbicides.
“No one in this neighborhood remembers how it might have gotten there,” said Dr. Mary Ketchersid, Texas Agricultural Extension Service pesticide safety education program specialist who helped identify the plant. “The scary thing for Houston is that there is no control for it and the conditions seem right for it to flourish.”
Pictures of the weed can be found on the web at >http://www.csdl.tamu.edu/FLORA/imaxxsol.htm<. In its native habitat, it is commonly called motojo-bobo, childa, huevo de sapo, nicua, ajicillo and barba de tigre.
Ketchersid began working on the issue after receiving a plant identification request in the mail. That plant was dead and had small leaves, she recalls, so her first impression was that it had some leaves and a growth habit similar to dichondra, a plant in the morning glory family. To be sure, however, she requested a live piece of the plant. That piece thrived once it was planted in a pot.
“As it grew, the leaves made me think of wild ginger,” she said, “but then the plant flowered, which is necessary before we can accurately identify it. Once it flowered, we knew that it was in the nightshade family which is the same family that includes tomatoes and peppers,” said Ketchersid, who worked with Monique Reed, Texas A&M botanist, to find the answer. Dr. M. Nee of the New York Botanical Gardens was the first of those contacted by the scientists to correctly identify the plant as Lysianthes asarifolia. The species name, asarifolia, means leaves that look like ginger.
Ketchersid would like to hear from people who have this plant in their yards, to survey how widespread it is or whether it is a problem for people who have it. That’s right. Some people apparently don’t consider the plant a weed.
Even some botanists in Louisiana where the plant once grew in a city park have an affinity for it and don’t consider it noxious if growing in contained spaces. Ketchersid believes that might be because Louisiana botanists claim the plant does not fruit and flower in that state, thus it is not as aggressive as it is in the different growing environment of coastal Texas.
“So the problem is that some people do not like it at all and some people do,” she said. “And in a population where it is making fruit and flowers, it is more aggressive, I think.”
The two scientists indicated that the weed is likely to thrive in Houston’s wet, shady environments.
“The Texas strain is more ready to take over whereas in Louisiana it has stayed in place. It’s a beautiful little plant but given half a chance, it could take over much of Houston,” said Reed. “At this point, it looks like it’s going to be a real nuisance in landscapes.
“That’s what a weed is — something that’s growing where you don’t want it. A concern is that it is an exotic plant, introduced into a new environment, because anytime a non-native plant grows over large areas, that means you are losing another plant, or what was there,” she said.
Reed suspects that the plant was introduced to Houston from a fruit because the plants are self-sterile — meaning that a shoot of the plant might grown but would not have been able to produce fruit without another plant. A fruit, however, would have contained seed that already had the genetic mix of two parent plants.
Here’s how Lysianthes asarifolia acts in Houston lawns:
* produces a lot of flowers and fruit
* individual seeds have a low germination rate, but the plant makes lots of seeds
* grows slowly from seed, but reproduces very fast vegetatively
* has sweet tasting fruit. In its native South America, the fruit is eaten raw or collected and made into jam.
* doesn’t like bright sun
* likes a lot of water, but doesn’t die if water-stressed for long periods as in last year’s drought.
* responds with smaller leaves and shorter internodes when mowed
* grows low along the ground, doesn’t creep up trees, but may produce an 8- to 12-inch high ground cover when undisturbed
“People should not give this plant to friends or swap it in gardening clubs. That will hasten its spread,” Reed said.
To provide Ketchersid with information about possible locations of this plant in Texas, or to find out how to identify a sample, call (979) 845-6531 or email m-ketchersid@tamu.edu.
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