(This column appeared in the June 16, 1997 Buffalo News. My more detailed account of this subject is in Niagara Frontier Botany Society talk.)
Most of us know rhubarb only as that sour and somewhat slimy vegetable served to us by people against whom we have no defense -- ever hopeful grandmothers and well-meaning hospital dietitians. In fairness, I also know it in combination with strawberries as my favorite pie. That's how it gets its alternate name: pieplant.
It turns out that the use of rhubarb stalks for food and wine has only about a 200 year history (still less in this country) while the medicinal value of its roots made it a very important staple in the doctor's pharmacopoeia for at least 20 times as long.
A 2700 B.C. Chinese herbal describes rhubarb among its plants useful for medical purposes and in 60 B.C. the Greek physician Dioscorides prescribed it not only for stomach aches and gas but also as an antidote to poisonous animal bites. Within a hundred years the Roman Pliny extended these uses to colds; liver, kidney, and spleen ailments; cramps and convulsions; wounds and bruises. Over time others added malarial and childhood fevers; dropsy, jaundice and chronic diarrhea; nerve, chest and asthmatic fevers; scurvy, psoriasis and even syphilis. It was for this last that Henry VIII was administered rhubarb on his deathbed.
That overoptimistic litany of maladies addressed indicates both how narrow were the options of early doctors and what little they had available to contribute to the welfare of their patients. Rhubarb served simply as a mild laxative. But that is no small thing and it was indeed the cathartic of choice. As Clifford Faust tells us in his interesting book, Rhubarb: The Wondrous Drug (Princeton,New Jersey:Princeton University Press, 1992), this concoction "addressed a fundamental medical need...without, at the same time increasing the pain and misery of the afflicted, as did other drastic cathartics and countless other remedies."
Physicians agreed then that rhubarb was a broadly useful tonic. Unfortunately this left them with a serious problem -- how to get it. All that was known about the plant was that it was grown somewhere east of the Volga River -- also known as the Ra River from which the name rhubarb is said to have derived. Roots were brought to the West by caravans out of the vast, unknown reaches of Asia first through Turkey and later Russia. In the late 13th Century Marco Polo reported it grown in a vague location in northern China and the trade routes seemed to confirm this. But where?
Of course the difficulty of obtaining rhubarb drove up its price. It was a medicine only for the rich. The poor had to substitute much less effective herbs like rhubarb's relative -- dock. As you might expect, unscrupulous distributors often laced their valuable rhubarb with that plant, thus serving as models for modern drug dealers.
Explorations were mounted to the Near East and the Orient seeking to locate and bring back these valuable plants. Many varieties were found but, until about 100 years ago, none matched the true rhubarb. Even when the highest quality plants were finally located in remote China, those brought back never bred true. So don't head for your gardens to dig out rhubarb roots to replace your Metamucil or ExLax. The roots probably won't hurt you, but they won't do you much good either.
It was the horticulturist Luther Burbank who finally developed rhubarb varieties for the food and drink potential of their stems -- their flavor and texture -- and for their rapid growth and long growing season, rather than for the medicinal properties of their roots.
Stick to those stalks and avoid the leaves as well. The leaves of many rhubarb varieties are poisonous.