Oh water lettuce.
You innocent unassuming looking little plant.
Walk into any water garden supplier and ask for an easy to keep, good for beginners aquatic plant. You will likely have water lettuce suggested to you. Water lettuce is available at just about every aquatic plant vendor out there, and you can even get it shipped to you from online aquatic plant vendors. Some people also call it water cabbage, and it’s scientific name is Pistia, …Pistia stratiotes to be exact.
This is a real interesting plant, and maybe it is not a plant for “beginners” after all. This plant has some history. This plant is kind of a bad child in the aquatic plant world; with a seedy past (really, it reproduces via seed). Water lettuce is, illegal!
It’s true, run for it. There are parts of this country where you cannot cross state lines with this plant or keep it in your backyard pond. Water lettuce, in some states, is considered a Class II prohibited Plant. If you are caught with water lettuce, here is officially what happens:
“The department is authorized to issue a written notice of violation, and issue instructions as to the manner and time in which the violation shall be rectified.”
That’s heavy. On the lighter side water lettuce is popularly known as a floating variety of aquatic plant, and sold that way. They are cheerful looking little plants resembling an open head of lettuce. The light green, thick leaves have a short coarse hair type of covering and ridges. They are inexpensive and sold by the head for large pieces or in groups. They are free floating plants inside of your pond, but they also work as a semi rooted plant and grow nicely in very shallow slow moving waters in a stream or shallow area of your pond. Be careful when using them with pond skimmers because they float into skimmers and can cause clogging, which will cause pump burn out!
Experts disagree as to whether water lettuce is a native North American plant but it was found here in the U.S. from Florida to Lake George, NY as early as 1765. It is found extensively in South America. It is native elsewhere around the world too, where in Africa it is one of the favorite food sources of the Hippo. Closer to home it is a favorite food source of the Florida Manatee, and there is plenty of it down Florida way. However it is not a food source for humans and would produce terrible intense burning to the lips, tongue, and mouth if one attempted to eat it raw. If one attempted to swallow water lettuce after the intense pain and burning of chewing it, then please post it to Youtube for us all to watch ya dummy!
In 1765 when cataloguing Pistia stratiotes, William Bartram a famous American naturalist and explorer, noted that water lettuce could be found clogging waterways to the point of not allowing passage of even small boats. And that very issue continues today, which is why its pretty understandable that water lettuce is not allowed in some areas. The growth of Pistia can be uncontrollable, ponds and lakes can easily be covered from shore to shore, unrecognizable as a body of water.
Most backyard pond keepers use water lettuce as a way to control nutrient levels in their pond water and to provide some shady cover for their ponds. The thick root systems of water lettuce grow long below the surface of the water sucking up nutrients from your pond water. Water lettuce roots also offer spawning ground for fish and frogs, and a source of food to nibble on. The leaves on top make for a landing spot for dragonflies and a place for frogs to hang out. Water lettuce likes a lot of sun, but not necessarily full sun.
In the backyard water garden they easily propagate, and need to be thinned frequently. Pistia reproduces by seed and by “mother” plants growing “daughter” plants that are attached to each other, sometimes forming large mats. It is not a cold hardy plant and will wilt and die in colder climates and should be removed from your water garden at first frost. Water lettuce makes one of the best container plants and micro pond plants out there. They even make for great table top water garden plants, or center piece displays.
Water lettuce is indeed a great beginner plant for the beginning water gardener and yet a challenge for the world’s greatest botanists. It’ll get ya in legal trouble and get ya out of water quality trouble at the same time. It goes by the name lettuce but will melt your face off if you try to eat it. Nobody really knows where it came from North America? South America? Africa? Well, its been here, there, and everywhere for along time now. It may be an innocent, unassuming looking little plant, but it’s a plant that has to be handled responsibly in your water garden and your local waterways.
Oh water lettuce.
What a Pistia!