You probably won't find Wolffia flowers at any summer weddings, but the water-dwelling plant would be a perfect accent at the world's tiniest garden party. Vases of thimbles might hold 5,000 blossoms, and a bouquet of a dozen blooming plants would sit on the tip of a boutonnière's pin. Floating like a chartreuse cloak upon a pond's calm surface, the flowers would provide a buoyant walkway to the opposite bank. A pond-side party of normal size, however, would require a microscope to appreciate details within shimmering sheet of transparent green jewels; less than a millimeter in diameter, the Wolffia globosa is the smallest flowering plant (angiosperm) in the world.
Wolffia (probably) columbiana. Photo credit: Kit Knotts
It isn't what you would expect from a flower—with no leaves, stems, roots, or petals, the Wolffia isn't fit for a garden bed or table arrangement—but its structure confirms it as one, albeit very small and very simple (and rarely in bloom, as the plants generally reproduce vegetatively). The exceptional flower consists of a single pistil and stamen, which sit in a depression on the upper surface of the plant's body. When pollinated, a single one-seeded fruit grows to the size of a grain of salt—one of the smallest fruits of botanic record, but large enough to all but overwhelm the body of its parent plant.
Jewel-like plants, Wolffia (probably) columbiana at 40x (left); flower cavity from the top (center); Wolffia arrhiza flower cavity from the side (left). Photo credit: Kit Knotts
The genus Wolffia includes eleven known species, all superlatively small, aquatic, and very high in protein (about 40%). Wolffia globosa is the tiniest of them all, and is known as khai-nam, or "water eggs," in Thailand, where it is harvested as a nutritious food. Wolffia plants can be gathered in waters across most of the world, so perhaps they can be included at your next dinner party—not in vases, but on the menu.
Skeptical? Apparently muffins are the the most common culinary application for the healthy Wolffia. And, at his test kitchen / plant lab in California, a botany professor has been cooking away on some protein-rich Wolffia dishes. Yummers!
An open-faced Wolffia sandwich, and pie à la Wolffia (Wolffia columbiana and W. borealis). Photo credit: W.P. Armstrong
Wolffia arrhiza at the Giardino Botanico di Mainz. Photo credit: mondocarnivoro.it
Anna Laurent is a writer and producer of educational botanical media. Photographs from her forthcoming field guide to Los Angeles are available for exhibition and purchase at the author's shop.