Sheep Sorrel is a perennial broadleaf weed that is also commonly known as Red Sorrel, Sour-grass, Indian Cane, Field Sorrel, Horse Sorrel, Cow Sorrel and Red-weed. Its scientific name is Rumex acetosella.
Sheep Sorrel is a rhizomatous broadleaf weed with a majority of basal leaves and less stem leaves that grow alternate one another. Its leaves are thick, petiolated, smooth and dull green in color. A papery or membranous sheath surrounds the stem just above the point of leaf attachment. Sheep Sorrel has a yellow taproot and numerous slender rhizomes. Blooming from May through September, Sheep Sorrel produces slender, vertically flowering stems that are four-sided and typically maroon to red in color. Each flower consists of six sepals without petals. Because it is a dioecious weed species, Sheep Sorrel produces exclusively male or female plants. The flowers on male plants have six stamens and transition from green to reddish-brown in color. The flowers on female broadleaf plants are red to yellowish-brown in color.
This broadleaf weed prefers acidic soils and commonly grows in fields, glades, waste areas and in gravel along buildings, driveways, roadsides and railroads. Sheep Sorrel can be found in nearly every state and province in North America.
Rumex acetosella is rather difficult to remove with cultural weed control methods alone. Physical removal (i.e., pulling weeds) is not recommended as rhizome segments are often left in the soil, sprouting new plants. Professionally selected and applied broadleaf weed killers—based on your specific climate and geography—are the most effective method for control.