While hiking the Losee Lake Trail at the Pinckney State Recreation Area here in Michigan, I found a lot of harlequin blueflag (Iris versicolor, Iridaceae) growing along the water. The large, showy flowers of this native plant were definite attention-getters:
Harlequin blueflag is more than just a pretty flower, however. This plant grows dense root structures that excel at trapping and removing many pollutants from the soil. When planted in vegetative filter strips along waterways, it can greatly reduce the amount of pesticide runoff that can contaminate reservoirs and other bodies of water (Smith et al. 2008). As a component of constructed wetland buffers, it can also help in the removal of fecal coliform bacteria and other contaminants (Zaimoglu 2006).
Smith K.E., R.A. Putnam, C. Phaneuf, G.R. Lanza, O.P. Dhankher, and J.M. Clark. 2008. Selection of plants for optimization of vegetative filter strips treating runoff from turfgrass. Journal of Environmental Quality 37(5):1855-61.
Zaimoglu, Z. 2006. Treatment of campus wastewater by a pilot-scale constructed wetland utilizing Typha latifolia, Juncus acutus and Iris versicolor. Journal of Environmental Biology 27(2):293-298.