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U.S. Forest Service

Plant of the Week

Silene acaulis range map. Silene acaulis range map. USDA PLANTS Database.

Silene acaulis. This extreme close-up of moss campion flowers was taken in the Pecos Wilderness on the Santa Fe National Forest, New Mexico. Photo by Charlie McDonald.

Silene acaulis. Close-up of a moss campion cushion. The tiny leaves and the flower buds hidden in the foliage are typical of cushion plants. Photo by Charlie McDonald.

Moss Campion (Silene acaulis)

By Charlie McDonald

Moss campion is a common plant throughout the northern arctic and the high mountains of Europe and North America. In the United States, it can be found in alpine tundra in the West and in New England.

The word tundra comes from the Finnish word “tunturia” which means treeless land. Alpine tundra is found on mountaintops above the elevation where trees will grow. Harsh growing conditions characterize the environment here. Winters have long periods of sub-zero temperatures, blizzards, and high winds. Summers are short with freezing temperatures possible at any time, harsh drying winds, and intense sunlight. The soils tend to be rocky, dry, and nutrient poor.

Alpine tundra plants have special adaptations to cope with the harsh conditions. Most of them are small and ground hugging with small leaves and with buds tucked within the foliage for maximum protection. Most are slow-growing perennials. It appears that a cushion-like growth form works well in the alpine tundra because many unrelated alpine plants have adopted it. The cushion shape helps protect tender parts from frost and high winds, helps retain moisture, and holds in heat. Studies have shown that the temperature within a plant cushion can be up to 10 degrees centigrade higher than the ambient temperature.

Moss campion is a typical cushion plant. It makes tidy little ground-hugging mounds with only its small leaves exposed to the weather. The flower buds hide between the leaves until many of them pop out at once to cover the cushion with color. To appreciate its beauty, moss campion needs to be looked at close-up. The individual flowers are only about 0.4 inch across. In addition, your alpine visit needs to be well timed because these plants bloom for only a few weeks each summer.

For More Information

PLANTS Profile - Silene acaulis, moss campion