II: Water Caltrop

Forgotten and beloved and despised at the same time.

II: Water Caltrop
Water caltrops. Photo courtesy Specialty Produce.

Good morning. Today is duodi, the 12th of Brumaire, Year CCXXXI. We celebrate le mâcre, a floating nut that's sometimes called a water chestnut.

A lot of the interest in caltrops now relates to the unusual shape of the underwater nut, which resembles a bull's head or a bat. The Japanese, however, focus on its "wings" which have a distinctive diamond or rhombus shape in some subspecies, so they call it their word for diamond, "hishi." This is the origin of both the name and logo of the Japanese company Mistubishi: three caltrops.

Let's get this out of the way: yes, this is also called a water chestnut, but we're not using that name because of the sedge (Eleocharis dulcis), which is what most people think of as "water chestnut" thanks to the crispy white vegetable's presence in many East Asian stir fry dishes. This nut, what the French call le mâcre, is from the Trapa family of floating plants, also native to Asia, but with a much more complicated history and a starchy, nutty flavor closer to the chestnut from which it gets one of its many names.

It is also native to Europe, and there's archaeological evidence that it was so prevalent in German prehistoric diets that it could have even been the sole source of sustenance when grain crops failed. And now it has vanished.