One of nature’s most remarkable and little-known group of plants is the diatoms, which are unicellular algae of vast numbers floating in marine and freshwater habitats. There are approximately 100,000 species of diatoms living today. The diatoms’ cells are encased in unique cell walls made of silica that have an astounding diversity of ornate forms and consist of two halves that typically overlap like the two halves of a pill box.
