👉 The term "capillus" is commonly used in the field of anatomy and physiology to describe a small, hair-like structure found on the surface of various types of plant cells. These structures are known as capillaries or capillary networks, which are essential for exchanging nutrients and oxygen throughout plants. Capillaries are tiny blood vessels that run through the cell walls of plant cells and are permeable to water, carbon dioxide, and other substances. They allow water and gases to circulate around the