The Tiniest Flowers

It is easy to get caught up in grandeur. Finding the largest of something is always fun but what about the smallest? I have talked about the largest flowers in the world but how small can a flower get? The answer lies in some of the most common plants on earth, the duckweeds (Wolffia spp. & Lemna spp.).

Duckweeds represent the epitome of flowering plant reductionism. They are little more than a pair or so of leaf-like structures that float at or near the water’s surface and the occasional taproot. What is even more striking are their flowers. Whereas most duckweed will reproduce clonally, every once in a while a flower will be produced. One species, Wolffia globosa, produces the smallest flowers of any duckweed. They are also the smallest flowers known to science. As you can see from the picture, they are nothing more than a couple anthers (A1 and A2) and a pistil (Pi). What's more, the male parts mature and die before the female parts, thus limiting the chances of self fertilization. As one would expect, the fruits produced are also the smallest fruits in the world.

Wolffia globosa

Wolffia globosa

This is all quite interesting considering the fact that DNA analysis places duckweeds in the aroid family (Araceae), which is home to the largest single inflorescence in the world! That's right, the arum family produces one of the largest groups of flowers in the world as well as the smallest flower and fruit in the world. Another cool fact about duckweed, specifically Wolffia, is that, gram for gram, it produces the same amount of protein as soy beans. Because of this, it is used as a food plant in many places around the world and more countries are waking up to its potential as both a food plant and a phytoremediation species. Pretty neat for such a small plant.

Photo Credit: Patrick Denny

Further Reading: [1] [2] [3]