What do rhubarb and buckwheat have in common and what do they have to do with polygons? They are both members of the buckwheat family. The family’s Latin name, Polygonaceae, is a nod to the plants’ many (poly) nodes or joints (gonum) as well as their numerous small, clustered flowers.
Naughty Plants
The family contains many so-called “nuisance” plants, namely knotweeds or knotgrass. Shakespeare, in A Midsummer Night’s Dream, wrote “Get you gone, dwarf; You minimus, of hindering knot-grass made.” There are, however, several underrated plants like rhubarb, buckwheat, sorrel, dock, and bistort that people prize for their sour flavor, a product of the plants’ oxalic acid.
Japanese knotweed is one such plant, maligned as an enemy of building foundations. British banks have restricted loans to homes discovered to have knotweed on the property. Not everyone considers knotweeds enemies. Foragers like to see the silver lining: They harvest Japanese knotweed for its rhubarb-like flavor.
The tantalizing aromas and flavors of Asian cuisines benefit from various knotweeds like Vietnamese coriander, which has a minty taste favored fresh in salads, spring rolls, and soups.
Tasty Sour Leaves
The approximately 200 species of docks and sorrels may be weeds, but they are also underrated and tasty.
Young dock and sorrel leaves go well in soups, sauces, and salads. Indians combine the leaves with yellow lentils and peanuts in soups and curries. Afghanis batter and fry them for Ramadan. Armenians braid and dry the leaves to be rehydrated later for aveluk soup. Indeed, many sour soups and stews are prepared with sorrel throughout Europe. The French cook it with fish because the leaves’ acidity dissolves thin fish bones.
Brother Buckwheat
Knotweeds and docks are considered famine foods, eaten in times of desperation. Wouldn’t you much rather have their big brother, buckwheat? Though not wheat, buckwheat does produce wheat-like seeds. It is a pseudocereal because it is used like a cereal but is not a member of the grass family—the true cereals.
Buckwheat likes poor soils and cold temperatures. It is the world’s highest elevation domesticated plant and dominates regions with short growing seasons, like Russia and the Himalayas. Buckwheat grains (called groats or kasha) are a staple of porridge and filling for dumplings and cabbage rolls. The flour becomes pancakes, crepes, Indian roti, and soba noodles.
Rhubarb
For all its obvious versatility, who could predict this hardy brown grain to be a cousin to weird ol’ clown-y bright-stemmed rhubarb?
After a drab, colorless winter, the sight of rosy pink stems emerging from the ground delights. Wisconsin is one of the top U.S. commercial producers of these tart and acidic stems. The leaves themselves are toxic due to oxalic acid.
I have tried everything from rhubarb jam, curd, syrup, shrub, and scones. After doing all this important research, I am here to tell you that rhubarb pairs particularly well with orange, ginger, and lamb. It does not—I repeat, does not—make a good BBQ sauce or ketchup. It should always be eaten in pie.
There are in fact dozens of species called “rhubarb.” The center of rhubarb diversity is in central Asia going back thousands of years. People originally valued rhubarb’s roots as medicine, eventually importing it to medieval Europe via the Silk Road. There, it sometimes reached several times the price of famously expensive spices cinnamon and saffron. It was not until sugar became more affordable that the English developed rhubarb for eating in the 18th century.
What about the other rhubarbs? What happened to them? People still appreciate wild rhubarbs as food and components of traditional medicinal systems. The Chinese call rhubarb “the great yellow” and have documented many medicinal applications. China even held an International Symposium on Rhubarb in 1990 to review scientific claims of medicinal rhubarb, many of which have not been pharmaceutically or scientifically verified. (Although according to some researchers, “there has been great progress in rhubarb research in recent years”). Can you imagine being a rhubarb researcher? Attending a symposium just about rhubarb? The world is a magical place.
Could it be that rhubarb pie is the correct medicine? The crazy rhubarb lady sure could use some medicine.