If you’ve been working in your garden lately, you’ve likely seen this shamrock-like plant. Did you know it is edible and delicious? This is Yellow Wood Sorrel (Oxalis dillenii).
PEI has four Oxalis species: two native and two non-native. The easiest to identify (and my personal favourite) is Common Wood Sorrel (Oxalis montana) with its beautiful and delicate pink-striped, white flowers. I see it most commonly along relatively undisturbed mossy stream banks.
The other three are all yellow-flowered. The non-native Yellow Wood Sorrel (Photo 1) is very similar to the native (but poorly named!) European Wood Sorrel (Oxalis stricta). The two are not that hard to tell apart in the field, but you do have to take a careful look. Because of that, I’m not at all confident that we have a good idea of the distribution of our native species versus its non-native look-alike. I do think it’s safe to say both are common, though. The final of our four is Creeping Wood Sorrel (Oxalis corniculata); as its name implies, it doesn’t stand up as straight as the other two and can take root from the stem.
If that’s too much plant identification for you, I have good news! All four species are equally edible and taste very similar. Wood Sorrels are high in oxalic acid (hence the genus name Oxalis) and this gives them a pleasant, slightly sour, lemony flavour. Oxalic acid binds to calcium and can cause problems in people with kidney issues or those who are prone to kidney stones. For most of us, this is not an issue; many plants – including rhubarb, spinach, and beet greens – are also high in oxalic acid. I ran the numbers, and an otherwise healthy person would need to eat two to three pounds of raw Wood Sorrel to have any ill effect. That’s a lot of Wood Sorrel! Even so, it’s probably best to enjoy this plant in moderation when raw (cooking reduces the amount of oxalic acid).
Wood Sorrel is one of our few wild greens that I truly enjoy as-is (Photo 2). While I usually mix things like Dandelion, Dock, or Plantain with other ingredients, a bowl of Sorrel with a light vinaigrette is lovely. I also use this plant to make a green sauce that pairs well with fish (Photo 3), a lemonade-like drink, and a simple syrup that has a ton of uses. You can find my recipes for Wood Sorrel in the Wild Food Recipes section of this blog.
I like watching the surprise on people’s faces when they taste Wood Sorrel for the first time during my workshops: they are always amazed at the flavour a wild plant can have. If you come across Wood Sorrel, give it a try. I think you will be pleasantly surprised at this part of PEI untamed!