Notes on Potentilla palustris in northern Michigan.

Abstract

Potentilla palustris, commonly known as the Marsh Cinquefoil, is a wetland plant of wide circumboreal distribution. In the New World it ranges as far south as New Jersey, Indiana and northern California, and as far north as the Arctic Ocean, where it has been found growing 15 miles from the Arctic shore. In the Old World its range extends from the Arctic Ocean as far south as Japan, Turkistan and central Spain. In many regions north-south mountain ranges extend its southernmost distribution. Potentilla palustris has been found at Ohio Pass in the Colorado Rockies, in the Sierra Nevada of northern California and in the mountains of Bulgaria. ... My interest here is to describe Potentilla palustris as it grows in northern Michigan, paying special attention to its ecology, associates, and probably position in successional sequences. I studied Potentilla palustris at 12 sites in the northern lower Peninsula and the eastern Upper Peninsula. In the Appendix I have described each of these sites and listed the species I found growing alongside Potentilla palustris. At most places I also noted the amount of moisture and light, as well as the number of flowering shoots, because it soon became apparent to me that most of the Potentilla palustris plants I was encountering were merely vegetative. I supplemented these observations with measurements of water chemistry, including pH, conductivity and alkalinity. I looked at water chemistry for what seemed to be two good reasons. First, it sheds light on the hydrology and nutrient conditions of a wetland. Conductivity is a measure of the ionic concentration in the water, alkalinity of the concentration of calcium carbonate. Both are rough measures of nutrients in the water or substrate and of the presence of ground water. The second reason is that water chemistry is widely used to define different types of wetlands. It seemed useful information for understanding the range of habitats in which Potentilla palustris may be found.