A characteristic of members of this genus is that they contain oxalic acid (whose name references the genus), giving the leaves and flowers a sour taste which can make them refreshing to chew.
 The crude calcium oxalate ranges from 13 to 25 mg/g fresh weight for woodsorrel as compared to 1.3 to 1.8 mg/g for spinach.
In very large amounts, oxalic acid may be considered slightly toxic, interfering with proper digestion and kidney function.
 However, oxalic acid is also present in more commonly consumed foods such as spinach, broccoli, brussels sprouts, grapefruit, chives, and rhubarb, among many others.
  General scientific consensus seems to be that the risk of sheer toxicity, actual poisoning from oxalic acid in persons with normal kidney function is "wildly unlikely".

While any oxalic acid-containing plant, such as Oxalis, is toxic to humans in some dosage, the U.S. National Institutes of Health note that oxalic acid is present in many foodstuffs found in the supermarket and its toxicity is generally of little or no consequence for people who eat a variety of foods.

In the past, it was a practice to extract crystals of calcium oxalate for use in treating diseases and as a salt called sal acetosella or "sorrel salt" (also known as "salt of lemon").
Growing oca tuber root caps are covered in a fluorescent slush rich in harmaline and harmine which apparently suppresses pests.
Creeping wood sorrel and perhaps other species are apparently hyperaccumulators of copper.
The Ming Dynasty text Precious Secrets of the Realm of the King of Xin from 1421 describes how O. corniculata can be used to locate copper deposits as well as for geobotanical prospecting.
It thus ought to have some potential for phytoremediation of contaminated soils.
A characteristic of members of this genus is that they contain oxalic acid (whose name references the genus), giving the leaves and flowers a sour taste which can make them refreshing to chew.  The crude calcium oxalate ranges from 13 to 25 mg/g fresh weight for woodsorrel as compared to 1.3 to 1.8 mg/g for spinach. In very large amounts, oxalic acid may be considered slightly toxic, interfering with proper digestion and kidney function.  However, oxalic acid is also present in more commonly consumed foods such as spinach, broccoli, brussels sprouts, grapefruit, chives, and rhubarb, among many others.   General scientific consensus seems to be that the risk of sheer toxicity, actual poisoning from oxalic acid in persons with normal kidney function is "wildly unlikely".
While any oxalic acid-containing plant, such as Oxalis, is toxic to humans in some dosage, the U.S. National Institutes of Health note that oxalic acid is present in many foodstuffs found in the supermarket and its toxicity is generally of little or no consequence for people who eat a variety of foods.
In the past, it was a practice to extract crystals of calcium oxalate for use in treating diseases and as a salt called sal acetosella or "sorrel salt" (also known as "salt of lemon"). Growing oca tuber root caps are covered in a fluorescent slush rich in harmaline and harmine which apparently suppresses pests. Creeping wood sorrel and perhaps other species are apparently hyperaccumulators of copper. The Ming Dynasty text Precious Secrets of the Realm of the King of Xin from 1421 describes how O. corniculata can be used to locate copper deposits as well as for geobotanical prospecting. It thus ought to have some potential for phytoremediation of contaminated soils.
Oxalis