The first herb we will be looking at is Slippery Elm, which is a tree that grows commonly in the northeastern part of North America. It grows to an average eight metres (40–60 feet), has a brown wood with red tinges, and grows a Samara fruit. The fruit is not used in traditional healing, though St. Mungo’s has a room where children can play with them. This is because when you throw them up, the Samara fruit spins as it falls to the ground. Samara is a dry, winged fruit, which may be used in several non-healing potions.

Slippery Elm grows in well-drained, loamy soil of a large pH range (5 - 8). Muggles have not managed to grow one anywhere outside of North America; however, Herbologists have cultivated the plant in Europe and Asia. The trick is the use of the spell Kana Groyio (Can-AH grow-YEE-oh), which alters the way the weather affects the plant.

The great thing about the Slippery Elm is that the tree rarely catches illnesses or diseases. For example, it very rarely gets the Dutch Elm disease (This is one of several ailments which plants may suffer from, and usually Elm type trees are the most susceptible). It was when Herbologists first noticed this that much research occurred in regards to the powers of the Slippery Elm. Two parts of the tree are used in healing: the leaves and the inner part of the bark. Potions using the inner part of the bark are used in baby food and formulas for preventing illness in children and adults. This would be a good time to mention, though, that pregnant woman should not consume Elm, as it is an abortifacient. If a pregnant woman consumes Elm, she should be taken to the hospital immediately for the adverse effects it could have on her body. Other potions with the leaves of this herb are used for wounds on the skin, burns, gout, boils, ulcers, and cold sores. A tea may be made for the following cases: heavy coughing, constipation, irritable bowel syndrome, bladder/urinary tract infections, syphilis, and herpes. Meals including the inner part of bark are helpful for banishing tapeworms, protecting against ulcers, soothing toothaches, aiding the digestive system, and healing a sore throat. Slippery Elm is also used as a lubricant to ease labor in women who want to have natural births.