This section is from the book "Nature's Garden", by Neltje Blanchan. Also available from Amazon: Nature's Garden; An Aid To Knowledge Of Our Wild Flowers And Their Insect Visitors.
Flowers - Small, dull purplish, about 1/2, in. across, on stout footstalks from axils of upper leaves; 3 narrow sepals and petals; stamens 12 to 18; pistils 4 to 18, forming 1 to 3-seeded pods. Stem: From submerged rootstock; slender, branching, several feet long, covered with clear jelly, as are footstalks and lower leaf surfaces. Leaves: On long petioles attached to centre of under side of leaf, floating or rising, oval to roundish, 2 to 4 in. long, 1 1/2 to 2 in. wide.
Preferred Habitat - Still, rather deep water of ponds and slow streams.
Flowering Season - All summer.
Distribution - Parts of Asia, Africa, and Australia, Nova Scotia to Cuba, and westward from California to Puget Sound.
Of this pretty water plant Dr. Abbott says, in "Wasteland Wanderings ": "1 gathered a number of floating, delicate leaves, and endeavored to secure the entire stem also; but this was too difficult a task for an August afternoon. The under side of the stem and leaf are purplish brown and were covered with translucent jelly, embedded in which were millions of what I took to be insects' eggs. They certainly had that appearance. I was far more interested to find that, usually, beneath each leaf there was hiding a little pike. The largest was not two inches in length. When disturbed, they swam a few inches, and seemed wholly 'at sea' if there was not another leaf near by to afford them shelter."