Sourgrass

Sourgrass is a common name given to several species of Oxalis, including Oxalis pes-caprae, also known as Cape Sorrel or Bermuda Buttercup; Oxalis grandis, the large yellow wood sorrel; Oxalis montana, the common wood sorrel; and Rumex acetosella, sheep sorrel. These grow as weeds in many parts of the United States. Oxalis pes-caprae is considered a major nuisance in parts of California.

They all have a pleasant lemony taste and are sometime used to season salads, and in folk herbal remedies. The taste comes in part from oxalic acid which is toxic in high levels, so consumption cannot be recommended.