The ancient Greek Theophrastus (c. 372–c. 287 b.c.e.) is known as the father of botany. His two works on botany, On the History of Plants and On the Causes of Plants, were so comprehensive that 1,800 years passed before any new significant botanical information was discovered. He integrated the practice of agriculture into botany and established theories regarding plant growth and the analysis of plant structure. He related plants to their natural environment and identified, classified, and described 550 different plants.