Question: Is there a reason that many types of African violets have fuzzy leaves? Does it increase the surface area to improve photosynthesis?
Answer: There are several advantages that are credited to African violets' fuzzy leaves. 1) The nap (or the direction that the hairs lean) is toward the tip of the leaf, away from the center of the plant, so that raindrops tend to run off of the plant instead of into the crown where the moisture could lead to rot. 2) The hairs provide a sort of air blanket against any changes in air temperature, which are common in nature. Violets thrive at 72 degrees Fahrenheit with a range of five degrees on either side of that. 3) Larger chewing pests, like beetles, are held above the actual plant tissue by the hairs. When they try to feed on violets, they get an undesirable mouthful of fuzz and soon move on to other easier food sources. The entire Gesneriad family (which includes African violets, but also Episcia, Gloxinia, Achimenes, Streptocarpus, etc) is characterized by some degree of fuzz on the leaf. All photosynthesis goes on in the surface cells of the leaf itself, so the hairs do not impact photosynthesis. Happy Growing! Joyce Stork