Large populations of flowers occur on North America's prairies, with as many as 200 different types of wildflowers growing on the prairies of Illinois alone, notes the Illinois Wildflower website. So many flower species populating prairie ecosystems can make trying to identify them seem an impossible task. However, you narrow your choices considerably when you look at these flowers and focus your powers of observation on specific aspects.
The color of flowers is the trait that most people notice first, according to the "National Audubon Society Field Guide to Wildflowers." That makes it a good place to start with prairie flowers, which tend to stand out more in their native grasslands and meadows because few trees and shrubs obscure them. Many colors have representation on the prairies. Flowers such as chicory and asters often are blue, Indian blanket is bright red, prairie wild roses are pink and ox-eye daisies sport yellow blooms. Knowing the predominant color of a flower is a key step in recognizing it.
Flowering Time Frame
You can use the time of year to help you determine what type of prairie flower you are encountering. For instance, ground-plum milk vetch will flower during April and May, but after that the flower withers away. Devil's claw, on the other hand, can bloom through October.
Prairie flowers vary in height, as some need to stretch up and above tall grass while others thrive closer to the ground. When classifying prairie flowers, knowing the overall size of the plant that they occur on is helpful. Smooth blue asters can grow up to 3 feet high, while the silky aster stays in the 1- to 2-foot high range. These are somewhat similar species, but the size can alert you as to which is which.
Clusters and Racemes
Many prairie flowers give away their identity by how their flowers occur on the plant, especially those that have flowers growing in flat-topped clusters. Among the plants that feature such clusters of flowers are the yellow rocket and the prairie parsley. Some flowers grow on elongated stems called racemes in an upright manner, covering the raceme from top to bottom. Such species include the prince's plume and the lemon paintbrush.
The symmetry of a prairie flower is another identification key. By looking directly into the face of the flower, you can discern if it is radially symmetrical---with parts of an equal length and radiating from the center outward. This is the case, for example, with the plains sunflower--one half looks like the other half does. Irregular prairie flowers do not have such an appearance, such as the blossoms on the blue lobelia. This flower has three lobes on the bottom and two lobes on top that curve backward.