Which plant's root contains mucilage and is used to relieve dry coughs?

The plant whose mucilaginous root is used traditionally to soothe dry coughs is marshmallow (*Althaea officinalis*).

Marshmallow is a perennial in the mallow family, native to Europe, western Asia, and North Africa. Its root contains mucilage, a group of water-absorbing polysaccharides that form a slippery, protective coating over irritated tissues. That demulcent action explains its traditional use for dry coughs and irritation in the mouth and throat.

The plant has a longer history than the confection that shares its name. Ancient Egyptians used marshmallow preparations, and the root was once cooked with honey to make a soft medicinal sweet. Modern marshmallows no longer generally contain marshmallow root; they are typically made with sugar, gelatin, or other gelling agents.

A common mix-up is slippery elm, licorice, or comfrey, all of which have their own traditional uses. The distinctive clue here is the combination of marshmallow root and mucilage. Traditional use does not mean every cough requires an herbal remedy, especially when symptoms are persistent or severe.