Use the following "flower color" resource as the first step to identifying wildflowers in the schoolyard. Note that not all wildflowers bloom the same time of year. Many bloom in the spring, while some - like goldenrod - are in full color in the fall.
This is just a start - using visual cues and is a good exercise in observation as well as plant structure. Students should also use leaf shape, leaf edge (toothed or smooth), leaf arrangement (opposite or alternate), plant height and even plant habitat (wetland, forest, field or dry, rocky area) if the flowers are not available.
Ask students to draw the plants they see, playing special attention to leaf shape, leaf edge (toothed or smooth), and leaf arrangement (opposite or alternate).