Multiple choice general knowledge sports Smallest flower Tulip Orchid Daffodil Wolfia Reveal answer Fill a bubble to check yourself D Correct answer Explanation Wolffia (also called watermeal) is the world's smallest flowering plant. These tiny aquatic plants are only 1-2 millimeters in diameter and float on water surfaces. Orchids, tulips, and daffodils are all much larger flowers visible to the naked eye.