On May 2, 2026 a group of about a dozen plant enthusiasts celebrated the beginning of Iowa Wildflower Month by exploring the flora of Cedar Bluffs State Preserve in Mahaska County. A crisp but sunny morning greeted the group led by Tom Rosburg. Much of the preserve characterizes the Southern Iowa Drift Plain and its native ecosystems – tallgrass prairie, oak savanna, and oak woodland. However, a special part of the preserve, featuring a 110-foot high, north-facing, sandstone bluff is much more similar to the Paleozoic Plateau than it is to the Southern Iowa Drift Plain. The bluff marks the southern side of the Des Moines River Valley, formed by the river’s erosive forces as it cut down into Pennsylvanian bedrock. Its cliff faces and ledges, rock talus, and car-size boulders seem out of place in southern Iowa. Not surprising it provides suitable habitat for several plant species more typically observed on the Paleozoic Plateau and in eastern Iowa. Here is a plant list for species observed and discussed. Those identified with an (*) were in flower. See the document below for the full plant list.
(Photos courtesy of Sarah Nizzi, Tom Scherer and Tom Rosburg)
