Besides offering good birding conditions, springtime treats visitors to a colorful succession of the so-called ephemerals, the early-blooming wildflowers that emerge in early spring and disappear by early summer. Early bloomers such as Hepatica, Bloodroot, Wild Ginger, and Dutchman’s Breeches give way to others, such as Spring Beauty, Bellwort, and Trout Lily. Not often spotted but known to this area, the Dwarf Trout Lily is a Minnesota endemic species, found only in Rice, Goodhue, and Steele Counties and nowhere else on earth. Spring ephemerals take advantage of the period of sunlight before trees and shrubs fully leaf out, and most then set seed and wither. However, some maintain parts of their plant throughout the summer, such as Jack-in-the-Pulpit, Rue Anemone, and Wild Ginger. Other species bloom in summer or even fall, such as the Bottle Gentian (see the Photo Gallery).
These wildflowers are just one part of a wide variety of vegetation in the 800-plus acres of Cannon River Wilderness Area. Some of the plant communities, such as the calcareous fen, bluff prairie, and floodplain forest, are quite rare in Minnesota. Some were identified by the 1990 Minnesota County Biological Survey as being of high quality. Low areas in the river floodplain include examples of flood plain forest, hardwood swamps, shrub wetland, wet meadow, calcareous fen, and lowland hardwood forest. The upland areas of the park are dominated by the maple-basswood forest type that once covered much of the Big Woods region of Minnesota, but there are also areas of oak forest, dry oak savanna, and dry prairie (see also Interpretive Signage for the text on signs in the park). Along the paths, visitors will find such individual species as Black Walnut, Hackberry, Wild Black Cherry, and varieties of ash and willow. The park’s surrounding areas are primarily agricultural, and within the park there are old-field remnants that are in the process of succeeding to forest. Some areas have been actively reforested through tree and shrub plantings.