This is Bacopa monnieri, otherwise known as Brahmi or Water Hyssop :
It’s a creeping perennial with small oblong leaves and purple flowers, found in warm wetlands, and native to Australia and India. The entire plant is used medicinally especially in India and it’s supposed to enhance memory, specifically the ability to retain new information. Here’s a link to a study that was done.
My plant is in a 15 cm pot and I keep it on one of my rainwater collecting bins (a 60 litre rubbish bin, with the lid turned upside down and a hole drilled in the centre). Because we’ve had good rain, the bin is full and the level of the water has filled the lid, so the pot is sitting in water :
The growth tends to cascade over the side and has entered the water where it’s put down roots :
I can cut off the rooted pieces and pot them up to make new plants. Wish all plants were as easy to propagate!
I harvest Brahmi by snipping off the growth ends with scissors, chopping finely and adding to omelets or scrambled eggs, but it can be added to anything you like. I don’t know if the memory improvement bit is working or not, but it’s something else I can grow that I can eat.