You do not have to depend on a wildflower being in bloom to identify it. When you own a reliable field guide, other aspects of a wildflower can help you find out what type of plant it is, with the leaves being one of the greatest aids. Identifying flowers by their leaves involves looking at such things as their thickness, their edges, their shape and their color. In some cases, leaves are actually more attractive than the flower and serve to attract insects and birds to help with pollination.
Look at how thick the leaves of a flower are. Those that are thicker than others will provide a valuable clue to recognizing the type of flower. An example of this is a flower known as the shooting star, which has leaves that are much thicker than the typical flower possesses.
Observe how the leaves are arranged on the stalk plant. Meadow beauties have opposite leaves, with two individual leaves developing at each node on the stem. Purple coneflowers have alternate leaves, with a leaf at a node all by itself, followed further up the stem by another lone leaf at the next node. The leaf arrangement on a flower is a constant within flower families and an important point to notice.
Determine if the leaves are rounded, elliptical, oval, wide, narrow or have nodes much like those of a maple leaf. This important facet of the leaf can often identify what a plant is. For instance, the leaves of an arrowhead, an aquatic flowering plant, have an obvious arrowhead shape with a pair of lobes at the bottom of the leaf that project backwards.
Discern whether the leaves of flowers have smooth or jagged edges. While many are smooth, like those of purple loosestrife, others have toothed edges. One such case is joe-pye-weed, which has course leaves with "teeth" along the borders of its leaves, giving them a serrated look. Toothworts have such serrated leaves that they give the plant its name.
Count how many leaves the flower has. Some will have many, such as penstemons, but others will have very few. Mayapple has just two large leaves that droop down and resemble an umbrella. Bloodroot has a single large leaf that seems to wrap itself around the stem like a cloak for the flower.
Distinguish if a flower has a "bract." These often look like petals but actually are a modified leaf, typically more colorful than the dull flower they encompass. The red bracts of the poinsettia plant are one example, while the white or pink bracts of the flowering dogwood are another. Bracts are usually smaller in size than the other leaves on the flower.