What a surprise to find a lush wildflower garden growing in the damp soil at the edge of the St. Croix river at the Arcola Bluffs trail. A trail along the river’s edge led me through dense clumps of Cardinal flower, Blue Lobelia, Obedient plant, and Prairie Ironweed.
There were hundreds of individual Cardinal flower stems growing here in the semi shade and moist forest soil along the St. Croix river.
With this many attractive red flowers, you would expect to see hummingbirds, and sure enough they showed up right as I began noticing the dense flower patch.
Shot earlier in my backyard wildflower garden, but Ruby-throated Hummingbirds do love this plant.
Among the hundreds of individual plants, there was one genetic mutant, a white form of the Cardinal flower.
White mutants of brightly colored animals or plants are usually genetic recessives, and are rare in the population. I imagine hummingbirds might skip over the nectar resources in this plant (wrong color to attract them), so it might not set much seed, which further contributes to its rarity.
Another Lobelia species, the Blue Lobelia, was also growing in the riverside wildflower garden, although in much lower density.
I spotted just a few individuals of Obedient plant in this “garden”, although this plant is usually an aggresive colonist of open spaces in my backyard wildflower garden.
Prairie Ironweed seems to like the wet river bottomland as well as it does the open prarie habitat. It’s large flowerheads were particularly attractive to honeybees.
Has this lovely wildflower garden always been here? Did I just happen to hit it during its peak flowering? Other wildflower enthusiasts have reported lush blooms of cardinal flower along the backwaters of the Mississippi and St. Croix recently (late July-early August), so maybe I have just never discovered these little patches of colorful diversity along the rivers.
Back Yard Biology 