CLIFF DWELLING PLANTS

Cliff talus slopes add much to the beauty and picturesqueness of our Mountains. To the mountaineer they are a constant challenge to his prowess. Their steep rocky inhospitable slopes would seem to offer little inducement to plant growth, but as all mountain climbers know, quite a number of plants find their way into their midst and dwell there some of them actually thriving in such an environment while others hang on precariously.

Even a cliff does not offer a homogeneous habitat. There are barren rock walls with only cracks and bedding planes here and there where a plant may find a bit of soil in which to grow. In other places rocks have fallen out leaving small platforms that have accumulated enough soil for a little rock garden and even trees invade these high perched hanging gardens. Most of the cliff plants are Xerophytic or dry land plants but here and there water trickles down the side of the cliff and offers enough moisture for a larger assemblage of plants. At the base of the cliff is the talus and on the rock ridges are pumice slopes and each has its complement of plant life. Nature is doing her best to obliterate the harshness which she has created in the age-long struggle to tear down our majestic mountain and has peopled even her cliffs with living things. Such a habitat offers little competition and those plants that have been hardy enough to adapt themselves to such surroundings are never crowded by their neighbors and so are like true pioneers.

Below is described a few of these hardy cliff dwellers and the habitat in which they are found. This is but a partial list of the more common ones.

Penstemon rupicola is the most highly colored and showy plant of the barren steep cliffs. Its short prostrate shrubby stems and rose crimson flowers make it very conspicuous on barren cliff sides, where only small rock crevices offer it a little soil in which to grow.

Penstemon menziesii with dull purple flowers is sometimes found in the same habitat but is not as common.

Companula ratundifolia, the bell flower or hairbell, is often found growing from tiny crevices on sheer cliff sides, its bell like blue flower nodding on the long stem. It is also found on the pumice slopes of the cliff ridges.

Castilleja rupicola, the paint brush, also adds a touch of red color to steep cliffs where more moisture and better footholds are to be found.

Mimulus alpinus, the alpine monkey flower, adds a splash of bright yellows on wet cliffs. It grows in a densely matted moss of short stems and abundant bloom and is very conspicuous and often associated with costillega rupicola.

Some of the Saxifrages also are cliff dwellers.

Saxifraga caespitosa grows on moist crags, and Saxifrage bronchialis is in drier places and sometimes embedded on moss covered rocks.

Saxifraga nelsoniana or the stonecrop is often found in cliffs while Sedum divergens is in the talus at the cliff's base and on the pumice ridges of the cliffs.

Oxyra digyna, the mountain sorrel, is found both in the rock crevices of the cliff but more often in the talus at the cliff's base.

Solidago algida, the mountain goldenrod, and Draba aureola, a yellow mustard are sometimes found on cliff sides where the cliffs are more or less broken down and narrow platforms have accumulated some soil. The latter will grow at very high altitudes.

Polemonium elegans, the arctic-alpine Jacob's ladder, grows at high altitude both in cliff and pumice slope.

Cheilanthes gracillima the lace fern also grows in rock crevices at a high altitude and is very common in some cliffs.

Lutkes pectinata, the Alaska spiraea, has a creeping habit of growth which enables it to form mats on flat places on cliffs and hold together and catch sufficient dust and soil to maintain itself there.

The above is but a part of these interesting plants and no attempt has been given their distribution in altitude but they vary from the Mountain's base up to the upper limits of plant growth in habitat.

By Charles Landes, Ranger-Naturalist.