The Vanishing Golden Carpet

The rarest plant in North America, found only four times by botanists, is a ground-hugging desert flower—the gold carpet. The plant appears, on rare occasions, in California’s Death Valley. Its appearance is that of a rosette of yellow leaves, sometimes as much as ten inches in diameter, lying flat on the ground. From this rosette arise innumerable tiny golden yellow blossoms, so that the whole seems like a patch of golden carpet in the brown desert. The reason for its rare occurrence is that its seeds can germinate only after a good rain. Such rains are rare in its habitat.

The plants must spring up within a few days. Ordinarily, even then, they die with the increasing drought before blossoming—thus forming no seeds. In order for them to produce the seeds for another generation there must be another rain following shortly upon the first.

The seeds become buried in the desert soil and, in the course of evolution, have developed the capacity of suspended animation over a number of years. In the old days, it is probable, these seeds retained their fertility only for a single season. Now there may be several years between rains sufficient to spur them to germination, and even longer periods between double rains which will enable them to form seeds.

The strange little plant first was discovered in 1891. There were only two specimens and search failed to reveal any more. Two years later, however, at about the same place another single plant was reported. No others were revealed by an intensive search through the entire area.

In 1931 and 1932 Dr. Frederick V. Coville of the U. S. Department of Agriculture and French Gilman, a California botanist, again made an intensive search but could not find a single plant. They came to the erroneous conclusion that the plant might be native to the mountains, from which occasional seeds were washed down after heavy rains. A few years later Mr. Gilman again took up the search and succeeded in locating the plant in four places. He found 14 individuals altogether and watched their growth carefully. Only three became large enough to flower and produce seed. The others dried up and died when they had only a few leaves and no branches. Later, however, Gilman found many specimens of the gold carpet scattered over low hills in the neighborhood.

These little hills all were whitish in color. This led to the idea that the chemical composition of the soil might have something to do with the appearance of the plants. Analysis, however, showed there was no basis for this assumption.

In the distant past, the gold carpet may have been a very abundant plant, germinating and flowering annually in a reasonably moist climate. Probably a few individuals developed the capacity of producing seed which would remain fertile over a lapse of years. When the climate changed these had a decided advantage over their fellows.

Apparently the gold carpet is a plant in the process of extinction. The continued existence of the species depends on the dormancy of a sufficient number of seeds to carry it over unfavorable years of inadequate, or inappropriately timed second rains. If Death Valley becomes drier and drier and years with suitable double rains become more and more infrequent the vitality of the seeds in the soil eventually will be insufficient to span the long periods when no seeds are produced.