Commonly called water cabbage or water lettuce. Why? Their soft thick leaves form a rosette with wavy margins just like a cabbage or lettuce. Too bad its not edible or I would have endless supply of them for salad! It is a genus of aquatic plant in the family of Araceae, found in the tropical, subtropical and warm temperate fresh waterways and ponds.
The tiny flower is hidden right in the middle of the rosette. Can you see it? No? Well..Im not too sure either if its there because it looks the same to me.....all green colour! Its supposed to bear little green berries after successful fertilisation. But so far I haven't seen them or maybe Im not observing them too closely. The male and female flowers are on the same plant for asexual reproduction. Mother and daughter are connected by stolons which will form dense mats on the water surface.
the roots underneath the rosette
The basket-like shape of the plant traps air bubbles which keep it afloat, while the roots are submerged in the water. Because of the growth habit of the plants, it is considered an invasive weeds clogging and affecting the biodiversity of waterways and ponds in some countries. The dense mats of Pistia block the air-water gas exchange in the water, reducing oxygen and killing fish. They also block light which kill the community of submerged plants.
invasive water cabbage covering my pond
By the end of each week, a thick mat of Pistia will form on my pond, covering almost all surface. I have to throw basketful of them or give out to my siblings and friends who want them, to save my koi. But the plants are also good as they protect small fish and fry under their leaves. They also outcompete with algae for nutrients in the water, thereby preventing the invasion of massive algal blooms.
a single layer Pistia just like the one my blog Header.....now you can clearly see the tiny round green flower in the middle
the koi also nibbles on the thick soft leaves of Pistia
Pistia Stratiotes in my garden, started with only 5 rosettes given by a cousin, and since then they have multiplied so fast and furious. Other countries considered them as an invasive troublesome weeds, clogging waterways which need to be destroyed. Here, we are clamouring for them as a must-have aquatic plant in our gardens' water feature!