Calcium oxalate is the most common component of kidney stones. Early investigators isolated oxalic acid from wood-sorrel ("Oxalis"). Members of the spinach family and the brassicas (cabbage, broccoli, brussels sprouts) are high in oxalates, as are sorrel and umbellifers like parsley. Rhubarb leaves contain about 0.5% oxalic acid, and jack-in-the-pulpit ("Arisaema triphyllum") contains calcium oxalate crystals. Similarly, the Virginia creeper, a common decorative vine, produces oxalic acid in its berries as well as oxalate crystals in the sap, in the form of raphides. Bacteria produce oxalates from oxidation of carbohydrates.