It’s highly probable that aquatic plants were among the earliest leafy vegetables in the human diet. Their visual appeal would have caught the attention of keen observers who, drawn like all of us to water, no doubt noticed how many birds and animals safely ate the plants that grew in it.
Even today, rice, a grassy cereal that’s the most widely cultivated and consumed crop on the planet, is still grown by farmers knee-deep in paddies (the water deters weeds and vermin).
Water plants are embedded in our culture. In the Bible, Moses was found among the
