Yellow Wood Sorrel

Oxalis corniculata

yellow wood sorrel

Yellow wood sorrel, photographed at Tropical Fruit and Spice Park, Redlands, Miami-Dade County, in July 2015.

There's not a heck of a lot of difference between yellow wood sorrel, Oxalis corniculata, and other members of the oxalis genus. They're all pretty much pests in gardens and lawns.

The one major difference: yellow wood sorrel is probably a Florida native, not that that is much solace if you find it growing in your yard, because like its cousins, it's extremely aggressive and equally hard to eliminate short of chemical warfare.

First a note: yellow wood sorrel shares many common names with another member of the oxalis family, Oxalis stricta, which, to our knowledge, doesn't grow in South Florida and perhaps nowhere in Florida. If you google yellow wood sorrel, you'll come up with both plants so make sure to check the scientific names.

And a note about the Oxalis genus. There are about 800 members worldwide, of which three are found in South Florida. The plants are known for their clover-like leaves and aggressive growing habits. Generally they are edible and tend to be sour-tasting because of the presence of oxalic acid. Many taste like the herb sorrel, hence the name. Our guy, yellow wood sorrel, is found throughout Florida and throughout much of the world. It's assumed to be native to the Sunshine State, says the Institute for Regional Conservation. In parts of Asia, Australia and the Pacific, it's considered an invasive. Even in the United States, where it's presumably native, it can be a pest, especially if gets established in a lawn or garden. It grows low, creeping along the ground. Mowing does nothing to discourage it but rather helps it spread. Cut parts of yellow wood sorrel and under the right circumstances new plants form. Seeds stick to mowers, essentially making them seed spreaders.

As flowers mature, they produce seed pods that contain 10 to 50 seeds each. When they ripen, they rupture and expel their contents as far as 10 feet. One plant can produce as many as 5,000 seeds. Part of the problem is that yellow wood sorrel will grow year round. That gives it a huge competitive advantage in lawns where grasses go dormant, or at least slow their rate of growth during the cooler months According to the University of California at Davis, yellow wood sorrel can be cut as short as a quarter inch and it will still flower and produce seeds.

The story isn't all bad, however. Yellow wood sorrel is edible either raw or as a cooked green or as a seasoning. It does have a sour taste to it that some liken to lemon. That's from the oxalic acid in the plant. Experts warn you don't want to eat too much, and anyone with a history of kidney stones or has had a bout of gout shouldn't eat it at all. Oxalic acid isn't good for either condition. People around the globe have found yellow wood sorrel medicinally valuable as well. The Cherokee used it internally and externally to treat hookworms, sore throats, to stop vomiting, as a cancer drug and with sheep's grease, to treat sores. The Cherokee and Iroquois used it as a food; the Menominee made yellow dye from it. Some research has found it has promise as an anti-inflammatory, analgesic, antimicrobial agent and warrants further study.

One quick taxonomic note: We've seen Oxalis corniculata used as a synonym for Oxalis albicans, AKA radishroot woodsorrel, AKA western yellow wood-sorrel. Synonyms in botancial terminology are scientific names for a plant that are no longer used or more commonly a name given by a scientist to a plant thinking he's seeing a new species or a new variety of a species when he or she really isn't. Our guy, O corniculata has 18 synonyms. Quite the confusing genus, Oxalis is. O albicans is not found in Florida.

Yellow wood sorrel is a member of Oxalidaceae. Other common names include creeping oxalis, creeping wood sorrel, yellow oxalis, oxalis, sour grass, pickle plant, common yellow wood sorrel and a whole bunch more. Spelling variations include woodsorrel and wood-sorrel.

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Published by Wild South Florida, PO Box 7241, Delray Beach, FL 33482.

Photographs by David Sedore. Photographs are property of the publishers and may not be used without permission.