Wood Sorrel (genus Oxalis), or sourgrass, is a medium sized weed that occurs throughout most of North America. Within the genus Oxalis, there are several hundred species.
Wood sorrel looks similar to clover and tends to get misidentified as clover.
It also gets confused with shamrock, but according to the Wisconsin Master Gardener Program website, shamrock is a "corruption of an Irish word that means 'little clover' and generally refers to white clover (Trifolium repens)".
And even though they share names, wood sorrel is not botanically related to sheep sorrel or garden sorrel, which are genus Rumex rather than Oxalis, a reminder that common names aren't always reliable when referring to plants.
Wood sorrel can grow up to 15 inches tall but typically only reaches eight or nine inches.
Its palmately compound leaves measure 3/4 to 1 inch across (2 to 2.5 cm).
Each leaf comprises three heart-shaped leaflets. Each leaflet is creased along its midvein like a folded paper heart.
The leaflets fold up at night and open during the day. They're most commonly green but can also be purple or burgundy.
Wood sorrel's five-petaled flowers are normally white or yellow although they can be pink or violet depending on species.
It usually blooms from spring to fall but, in warmer regions, it can bloom any time of year.
Wood sorrel fruit, or seed pods, resemble tiny okra pods. They tend to be around 3/4 inches long, growing upright from their stalks.
The seed pods "explode" when ripe, sending their seed several feet into the air.
Is wood sorrel edible? Yes! Oxalis literally means "sour" and it gets that name from its oxalic acid content.
Lots of domesticated vegetables, including spinach, broccoli, and, um, sorrel, also contain oxalic acid. But be aware that oxalic acid can be toxic when consumed in large quantities because it inhibits the absorption of calcium.
It's not considered a problem when eaten moderately and with a varied diet, however people with gout, rheumatism, and kidney stones should avoid oxalic acid.
Wood sorrel is also rich in Vitamin C. Historically, it was used to treat scurvy, fevers, urinary infections, mouth sores, nausea and sore throats. It's qualities and flavor are similar to sheep sorrel.
All parts of wood sorrel are edible including leaves, flowers, seed pods, and roots.
Wood sorrel has a long known history of culinary use in ancient cultures.
One species native to the Andes, Oxalis tuberosa, has been cultivated for its edible tubers since pre-Cololumbian times.
According to research-for-development organization the International Potato Center, Oxalis tuberosa (known as Oca) is "the second most widely cultivated tuber next to potato" and is high in protein and antioxidants, as well as a good source of amino acid and fiber.
Almost all of North America has at least one of the hundreds of species of wood sorrel.
Wood sorrel is a common lawn weed that likes partial shade. Look for it in yards, gardens, and parks.
How to harvest
In places where wood sorrel is abundant or unwanted (like your lawn or garden), simply pull it up by its roots.
Otherwise, judiciously pick or cut sprigs, leaving enough to ensure the plant or colony remains viable.
Wood sorrel should be used fresh. Pick off the leaves, flowers, and immature seed pods to put in salads, avoiding older, tough stems.
Eat it raw or cooked.
Wood sorrel has a tart, lemon-like flavor and goes well with meat and fish.
Or try our wood sorrel tart recipe.
Wood sorrel tea
- 1 tablespoon fresh wood sorrel leaves, flowers, and/or seed pods
- 1 cup water
Boil water, pour over fresh woods sorrel and let steep for up to a half hour. Strain, sweeten to taste, and enjoy!
Wood sorrel also makes a nice yellow to orange natural dye.
And according to the Aunt Jenny blog, the oxalic acid in Oxalis acts as a mordant so it doesn't need alum or any other fixatives.