In our pond business we sold lots of plants. Many companies now days become pond installers because they were landscapers and in general do not have much information about aquatic plants. In turn the pond installers often end up selling plants to the pond owner.
With little knowledge, plants that are pretty or distinctive are sold and many of these are invasive to certain parts of the country.
In our area the common pond plants are water hyacinth, Anachris, horse’s tail, yellow flag iris, cattail, parrot feather, and various water lilies and lotus.
Of these plants, of which there are eight, six of them are invasive species. I could break down the water lilies and lotus, but the point is that we all need to learn more about invasive species and what their threat is.
I like to fly fish and was alarmed when I was out in Idaho and discovered that Henry’s Fork has loads of Anachris canadensis.
It appeared to me that it was identical to what we have been selling to pond and water garden enthusiast for years.
Anachris is also know as Egeria densa and is also called Brazilian Elodea. With all these separate names it becomes confusing to know what a plant should be called. There are a couple of links that I want to mention. One is by Florida Aquatic Nursery and give this issue a little of the commercial flavor. The most comprehensive site that I found that explained all the details of this plant is xxxxx.
From my observations of this plant it overwinters well here and seems to like the shaded slightly cooler water of mid summer. If it gets to hot as created by being in shallow water a great deal of it will turn to mush. If it gets into our waterways and lakes, Anachris can become a serious problem. The linked referenced above is the site for Florida Aquatic Nurseries and is worth reading. Another very good site which explains how to differentiate between the various species is www.wetwebmedia.com/PlantedTksSubWebIndex/elodea.htm written by Bob Fenner.
One plant I have experiance with is Horsetail. (get latin name). In our area this is a very hardy plant that spreads underground by rhyzomes and can be very difficult to eradicate. I received a pot of it from a friend and was interested in it because of a photo I took years ago. photo Had I kept the pot in the water I suspect it would have been fine but it sold pretty well do I had several pots of Horsetail. Roots came from holes in the bottom of the container and eventually took over the area. It eventually got into the vegetable garden I had at my office. If you tried to pull it up some of the rhyzomes broke off and eventually new plants would emerge.
It can be controlled by spraying but I did not want weed killers in my garden. It eventually got ahead of me and I wish I had kept it under control.
As a footnote, I like to fly fish and on several occasions I have been on an Island in the middle of the Holston river in Tennessee and the entire island had an underlayer of Horsetail covering the entire small island. (If my memory doesn’t serve me properly this information is accurate, but I will check it out on my next rip to the South Holson. River
As time allows I will add more information about other invasive aquatics.