t least 16 species of sunflowers cheer up Texas roadsides, ditches, and vacant lots throughout the year. Maximilian sunflowers grow mainly in Central Texas, and swamp sunflowers add color to river bottoms farther east. But the common sunflower takes root practically everywhere. Once established, the plants protect their territories by releasing toxins that, or “look at the sun.” Once the flowers begin to open, the heliotropism ceases and they remain facing east.
