The watercress I'd brought home earlier this year flowered and went to seed when the weather turned hotter. It made LOTS of seeds! Here's a carpet of seedlings from some of that seed replanted recently. Makes me want to start some more! Maybe I'll get to eat more than just a taste this time.
Did I mention that watercress is reported to be a "superfood"? If I'm remembering right it has more calcium than milk, more iron than spinach, more vitamin C than oranges, lots of vitamin A and if that wasn't enough it has the anti-cancer compounds that the cabbage family is famous for too.