There are several different kinds of watercress, three of which I mentioned in this article:
So far I have grown only two. The one I grew from seed is Nasturtium officinale, which is a lovely plant, but finicky and slow to get established from seeds. It does root beautifully from cuttings, however, and if it gets an alkaline environment and the weather is cool enough, it produces luscious leaves with a deep rich green color.
Nasturtium officinale just started from newly rooted stem cuttings.
The Barbarea verna we have been able to purchase from live-root plants at the supermarket, and that one seems to be reproducing itself by division.
Barbarea verna can be found as live plants in the produce section of the supermarket.
I have high hopes for Leopidium sativum working better for us because it is reportedly heat-tolerant but I am looking for the broad leafed cress and need to be sure that when I order seed it does not turn out to be cressida, the curly variety of this plant.