The Sour Shamrock
By Audrey Stallsmith
Though you may be choke-full of science, not one in twenty of you knows where to find the wood-sorrel, or bee-orchis, which grow in the next wood, or on the down three miles off. . .
Tom Brown's Schooldays, Thomas Hughes
You can probably buy pots of oxalis, AKA wood sorrel, in your local supermarket or department store this time of year. I suspect the poor thing may feel out of place under all that fluorescent light and canned music. But, as the plant is one of those reputed to be St. Patrick's shamrock, it is always trotted out in March.
Other contenders for the shamrock title include white clover (trifolium repens), hop clover (trifolium campestre), and black medick (medicargo lupulina). But the oxalis, which grows from small tubers, makes an easier potted plant. So it's the one that merchants opt for!
Oxalis is also known as wood sour, cuckoo's meat, sour trefoil, sleeping beauty, or--my favorite--hallelujah or alleluia. The plant earned the latter nickname because, in Europe, it blooms between Easter and Whitsuntide (the feast of Pentecost which falls 50 days after Easter). So its flowers open during the time period that alleluia Psalms are traditionally sung. As the reddish veins that decorate those blooms are supposed to represent Christ's blood, wood sorrel frequently appears in paintings of the crucifixion as well.
The "sleeping beauty" designation refers to the fact that the plant folds its leaves at night or when stressed. Perhaps that prayerful attitude also contributed to its religious implications!
Oxalis acetosella grows wild in Europe. Its name derives from the Greek oxys ('sour) and acetosella ("vinegar salts"). Both names refer to the plants acidic, almost lemon-y, flavor. Oxalis montana the American native variety, looks very similar to acetosella, but with notched petals. Yellow-flowered types are also quite common, stricta in the States and europaea in Europe.
The wildings can reproduce themselves prolifically, as they often produce a second set of low-growing buds in summer. Those, however, self-pollinate and seldom actually open.
You can purchase the fancier regnellii and tetraphylla varieties of oxalis as ornamentals intended for shady garden beds or windowsills. They are, though, frequently valued more for their fancy leaves than for the more inconspicuous flowers.
Leaves of wild wood sorrels provide the base for Green Sauce, usually eaten with fish--probably for that lemon-y flavor. The plant is frequently added to spring salads as well. But oxalis should be eaten in moderation and avoided by people with kidney problems, rhematoid arthritis, or gout, due to its high oxalic acid content.
For those not bothered by that acidity, oxalis also reputedly quenches thirst, cools fevers, cleanses the blood, stimulates the appetite, and stops vomiting. Applied externally, it can stanch wounds and reduce swelling. It is also, as its citrus taste implies, quite high in Vitamin C.
The plant has been employed in the production of yellow dyes and salts of lemon as well. And it will reportedly attract leprechauns to your property. But, considering the mischevious character of those Erin-ish elves, that may not be such a good thing!
Oxalis itself is a very good thing, however. And it springs into life at a time of year when, winter finally past, we all want to belt out a few hallelujahs!
Oxalis acetosella image is from Otto Wilhelm Thome's Flora von Deutschland Österreich und der Schweiz, courtesy of the TAMU Vascular Plant Image Library.