Watercress wasn't "discovered" in the sense of a single moment or place. It's a natural plant, and humans have been eating it for a very long time.

Here's what we know:

* Ancient origins: Watercress has been eaten for thousands of years, with evidence suggesting its consumption in ancient Greece, Rome, and China.

* Natural habitat: It grows naturally in cool, clear streams and springs across Europe, Asia, and North Africa.

* Cultivation: While it grows wild, humans have been cultivating watercress for centuries. The Romans are known to have cultivated it, and it's been a staple food in many cultures.

So, rather than a single "discovery," watercress has a long history of use as a food source across different cultures.