Now in Bloom: Moss Campion

Moss campion is familiar to anyone who has visited a North American alpine area in the summer. Its cushions of bright green leaves become covered with many pink, star-like flowers as soon as the temperatures warm, often flowering first on the warmest, south-facing side of the mat.

Moss campion is now blooming in the Berry Prairie, where the photo above was taken.
Photo by Dorothy Tuthill

Cushion plants are common in the alpine, for reasons that are probably clear if you’ve been there. Those habitats are subjected to strong, desiccating winds, high ultra-violet radiation and rapidly fluctuating temperatures, not to mention extreme cold. Studies on alpine cushion plants show that temperatures within plant cushions are more moderate and humidity is higher than outside the cushion. That microclimate is good not only for the plant that makes it—cushions also make good nurseries for the seedlings of other plant species.  On the down-side, Silene acaulis, like most cushion plants, has a slow growth rate, estimated at about one quarter inch per year. A rare, large cushion of moss campion may be as big as six to eight inches in diameter, and many decades old. Plants in Colorado have been estimated to reach 100 years in age, and Alaskan plants may reach 300 years!

Moss campion in bloom near Lookout Lake in the Snowy Mountains, west of Laramie.
Photo by Brenna Wanous

If you’re lucky enough to live in the Laramie Basin but have an aversion to high places, no worries—you can see lots of cushion plants closer to home. Hooker’s sandwort (Eremogone hookeri) looks similar to moss campion, but with white flowers, and the petals are pointed rather than toothed, as are moss campion’s. Hood’s phlox (Phlox hoodii) also grows as dense cushions of small, spiky leaves, transformed once or twice a year into delicate pillows of small white blossoms. Hood’s phlox can grow so densely in disturbed areas that flowering plants can be mistaken for snow. 

Hooker's sandwort grows in the Berry Prairie and the surrounding Laramie basin.

Hood's phlox are a common and beautiful cushion plant found in the Laramie basin and beyond.

Hood’s phlox and Hooker’s sandwort grow not only on the Berry Prairie, but in many places around the Laramie Basin, often in the company of other cushion plants. Look especially on the tops of ridges. In fact, cushion plant communities are quite common in the harshest, driest landscapes of Wyoming. Why? Well, those habits are subject to strong, desiccating winds, high ultra…

You get the idea.

Written by Dorothy Tuthill, Berry Center Associate Director