Burdock is a common weed native to Europe and Asia. It is a plant of waste places, fields and waysides.
The burrs are what you will find sticking to your clothing as you walk through your horse's field. The large lobe-like leaves look like overgrown Rhubarb leaves. Generally Burdock is looked upon as a blood and liver cleanser and is cleansing and soothing to the lymphatics. All parts of the plant used.
The root is a deeply anchored root. It reminds one of the Dandelion and Yellow Dock Root. In Japan it is known as Gobo and is eaten commonly in Sushi. The root is white and pithy in color when raw, turning very orange when cooked, resembling a very small fine carrot. Horses will eat the roots just like carrots. The roots are considered to be a soothing demulcent, tonic and alterative (blood cleanser).
The leaves are classified as cooling, moderately drying and dispersing. Juice of the leaves was drunk in old wine. The leaf is thought to have strong actions on the lung and skin. It is often used in skin conditions like eczema.
The plum colored flowers bloom through July and August, replaced by seeds or the fruit. They are used for kidney issues. It has been used for both profuse sweating and lack of sweating.
Burdock is not a plant you would think a horse would graze upon, but they seem to know how to carefully work around the bristles of the burrs. There is no known toxicity to date for any parts of the plant.