The Value of Mountain Laurel

On May 5, 1933, Governor Pinchot signed a law that made Mountain-Laurel the state flower. The mountain-laurel’s stunning, but short, display of beauty is worthy of becoming the Keystone state’s flower. Over the last month, we’ve all admired the beauty of the mountain-laurel, but it has other values within the Allegheny ecosystem that deserve our recognition, too.

Animals that associate with mountain-laurel include white-tailed deer, eastern screech owl, black bear, ruffed grouse, turkeys, snowshoe hare, and song birds. Black bears are known to den in "ground nests" in mountain-laurel thickets. Snowshoe hare, ruffed grouse, and warblers hide in the dense thickets. Many a hunter has waited in anticipation just outside a clearing in the laurel for a tom turkey to ‘spit and drum’ close enough for a shot.

Mountain-laurel's leaves, buds, flowers, and fruits are poisonous, and may be lethal to livestock and humans. However, white-tailed deer, eastern cottontails, black bear, and ruffed grouse are known to eat mountain-laurel in the winter or during years of food shortages.

Mountain-laurel is noted for preventing water runoff and soil erosion on mountain hillsides. Researchers in the southern Appalachian Mountains found that excessive cutting of dense stands of mountain-laurel greatly increased the amount of water runoff. In urban and suburban parks and recreation areas mountain-laurel is commonly used in forest restoration projects that focus on stabilizing thin soils. The leaf litter of mountain-laurel contains higher than normal levels of minerals than forest trees. The leaf litter contributes nutrients back to the forest soil as the leaves decompose.

Mountain-laurel is dependent on mycorrhizal fungus associated with its root system in the soil; mycorrhizal means a fungus and root association where the fungus helps the roots, and the roots help the fungus. The mycorrhizal fungus association of mountain-laurel helps the laurel obtain water and minerals from even the nutrient-poor, acidic soil of the Allegheny Plateau.

Humans have also developed uses for mountain laurel, despite its poisonous nature. Extracts of mountain laurel can be used to treat diarrhea, upset stomach, skin irritations, and as a sedative. Do NOT try to develop an extract on your own.
The wood of mountain-laurel has a long history of uses by native and Euro-Americans. It has been used in the manufacturing of pipes, wreaths, roping, furniture, bowls, utensils, and other household goods and novelties. Economically, mountain-laurel is the most important member of the genus Kalmia. Laurel is sold commonly as an ornamental and the leaves are used in floral displays.

How does this valuable forest shrub replace itself? Pollination of laurel flowers is normally accomplished by bumblebees. The anther (male part of the flower that contains pollen) of a laurel flower is positioned under tension which is released when a bumblebee or other insect lands on the flower. The pollen is then showered over the pistil (female part of the flower). If a pistil remains unpollinated, the anther self releases pollen onto the flower’s own pistil.