Driftless Area; Iowa flora; rare plants; Pleistocene flora
A portion of the Upper Midwest escaped glaciation during the two most recent glacial epochs. This "Driftless Area", also known in Iowa as the "Paleozoic Plateau", comprises some 39,000 square kilometers (15,000 square miles) in the states of Illinois, Iowa, Minnesota, and Wisconsin. Today the highly dissected terrain provides a variety of habitats supporting a rich and diverse flora including many plants special to the area, i.e., principally, in Iowa, restricted to the Driftless Area. These special plants have received much attention, often having been discussed as possible relicts from past floras. However, distribution data for these species beyond the Driftless Area has been compiled for only a few. We present habitat descriptions and mid-western (and North American where appropriate) distribution maps of 74 plant species special to the Iowa portion of the Driftless Area, along with speculation on their origin, with particular reference to late Quaternary events. The exceptional plant diversity and unusual species in the Driftless Area in Iowa result from a complex of factors which include the extreme habitat diversity, the location of the area near the juncture of three regional floras, river corridors which provide migrational pathways from other regional floras, and the relictual nature of a number of species.
Journal of the Iowa Academy of Science
© Copyright 1993 by the Iowa Academy of Science, Inc.
Pusateri, William P.; Roosa, Dean M.; and Farrar, Donald R.
"Habitat and Distribution of Plants Special to Iowa's Driftless Area,"
The Journal of the Iowa Academy of Science: JIAS: Vol. 100:
, Article 3.
Available at: http://scholarworks.uni.edu/jias/vol100/iss2/3