The term 'Science of Plants' can be summarized as Botany, which is a 6-letter word. Botany is the scientific study of plants, including their structure, growth, reproduction, metabolism, development, diseases, and chemical properties. It also includes the study of how plants interact with their environment and other organisms. Botany has been around since ancient times, and it has been used to identify, classify, and study plants. Botany has also been used to develop new medicines, improve crop yields, and understand the effects of climate change on plants.