Yellow Dock Plants

Identification Help for a Simple Home Remedy for Stinging Nettle Rash

Photo of yellow dock seeds.
The dried flower spikes of a yellow dock plant look very much like coffee grounds. David Beaulieu

Taxonomy, Botanical Classification for Yellow Dock Plants

Plant taxonomy classifies yellow dock as Rumex crispus. It is considered a broadleaf, perennial "weed," "wildflower," or "herb," depending on your perspective. This curious plant belongs to the buckwheat family, which is characterized by the nodes that punctuate the plants' stems (an even clearer example being those found on Japanese knotweed). It is in the same genus as another weed commonly found in North America, namely, sheep sorrel (Rumex acetosella).

Yellow Dock Plant Identification, Where It Grows

The picture here will help you with the identification of yellow dock. The image shows the distinct flower-head of the plant, after the blooms have dried and turned brown. The flowers start out a much less distinctive light-greenish color.

The plant's dark green leaves will further help you identify it when you encounter it. The bottom leaves can be quite long, ranging from 1/2 foot to 1 foot in length. Look, in particular, for the lanceolate shape and the curly edges of the foliage. It is from this curly leaf margin that the weed derives the nickname of "curly dock." This alternate common name is also sometimes given as "curled dock" or "curley dock"; the species name, crispus is Latin for "curly." For the origin of the common name, "yellow dock," see below.

Another aid in identifying this weed is its height. The plant reaches as much as 4 feet tall at maturity. A related weed can also grow to be as much as 4 feet tall: namely, bitter, or "broadleaf" dock (Rumex obtusifolius). But it is easy to tell the two apart: True to its name, the broadleaf type has bottom, or "basal" leaves that are very wide (4 inches across, versus 1 inch across for yellow dock plants). Whereas the subject of this article has basal leaves shaped like swords, the basal leaves of its relative are shaped more like shields.

Indigenous to Europe, Rumex crispus has become naturalized across much of the world. It often grows in disturbed soils and is frequently found along roadsides, although it prefers humusy soils. In some states of the U.S., yellow dock is considered an invasive plant.

Weed Control Tip, Warning

Rumex crispus produces a long taproot. If you are going to try to dig it out, you must dig deeply, so as to remove the whole root; otherwise, as a perennial weed, the plant will re-emerge. Those of you aware of the challenges involved in dandelion control will understand this problem.

Despite its medicinal qualities (see below), Rumex crispus is listed as a plant poisonous to dogs by the ASPCA.

Home Remedy Against Rash From Stinging Nettles

Has your skin ever brushed up against stinging nettles (Urtica dioica) while you worked in the garden? If so, you know about the burning sensation caused by their spines, followed by an itchy rash. Fortunately, Rumex crispus often grows near stinging nettle. Just roll a leaf of yellow dock between your thumb and forefinger to crush it, then doctor your wound with the juicy pulp left over, and the burning will subside.

Yellow dock has, in fact, been used medicinally (for a number of ailments) for ages, which is why many prefer to refer to it as an "herb." But it is mainly the plant's root, rather than its leaves, that has been used in folk medicine. In fact, the common name, "yellow dock" refers to the yellowish color often found inside the root, when it is sliced open.

The yellowish root notwithstanding, the signature color of Rumex crispus, in the eyes of many aficionados of wild plants, is brown. That is the color of the dried flower-head in fall. Once you are able to use this feature to identify it as yellow dock, you will never forget this plant.

One has to love the texture of this dried flower spike: if you grab the coarse brown spike and slide your hand along it, you will come away with a handful of small, crispy flakes (the seeds and dried sepals). They make one think of coffee grounds -- which is ironic, since folks have roasted this plant's seeds for use as a coffee substitute in the past. Another weed commonly found along the roadsides of North America that has been used as a coffee substitute is chicory, which is also a European native.