This site has excellent resources for teaching students about plants. It has a guide to scientific investigation and a glossary of plant terms. There are three lessons that each include a slideshow on the parts of a plant, the needs of plants, and how people use plants. There are high-quality images of different seeds, leaves, roots, and stems. There is a set of four BBC documentary videos, each between 48 and 50 minutes long, on "The Private Life of Plants." There are also links at the bottom to additional website resources.