Population Studies of Opuntia fragilis

Dr. Eric Ribbens, Western Illinois University

2006-

Opuntia fragilis, a tiny prickly-pear cactus occurs at only one station in Michigan -- in a small patch on the south slopes of Huron Moutain. While the cactus has been known from this site for many years, there has been no careful study of the status of this small population.
	A blooming specimen of Opuntia fragilis in 2006. Photo by Eric Ribbens

Eric Ribbens and his students conducted an initial survey of the Opuntia population in 2006, carefully recording location, condition, and size of individual plants. They will be monitoring the population to ascertain it's current status. Because the 'pads' (stem sections) readily separate and root (in the process, rolling down the steep rock face where they grow), apparently different 'individuals' may actually be parts of the same plant and genetically identical. Indeed, the entire 'population' could be a single clone. DNA analysis of tissue samples will permit analysis of the true, genetic size of the population.