Nasturtium is Latin for ‘nose twister’, referring to the plant’s pungency. Watercress shares membership of the crucifer plant family with mustard, and both plants owe their pungency to substances of the same kind.
Watercress grows wild in Europe and Asia, and also in America since its introduction by European immigrants. Wild watercresses have been continuously popular since ancient times, not only for their pleasantly biting taste, but also for a wide variety of supposed health-giving properties. Thus the Greek general Xenophon made his soldiers eat it as a tonic. The Romans and Anglo-Saxons both ate it to avert baldness. Gerard (1633) recommended watercress as a remedy for that now forgotten disease, ‘greensickness of maidens’. Francis Bacon advised that it would restore youth to ageing women; and so on. In fact watercress does contain useful amounts of vitamins A and C, together with iron and other minerals, but no one has identified any mysterious curative substances in it.