The tiny hairs on raspberries are called pistils, and it is these pistils that help turn the berries into an edible fruit. Raspberries are actually clusters of aggregate fruit, meaning one fruit grows onto a single pistil. Each berry is the result of pollinated white flowers that contain numerous hair-like pistils. After the berries mature, the visible hairs are what remain of the original pistils.
The hair-like pistils commonly seen on raspberries are from the female part of the flower. Pistils are easier to spot on certain varieties of raspberries. It is possible that the pistils remain on the fruit as a natural defense against insect predators. Insects and fungi eat raspberry plant leaves and sap.
Raspberries are extremely versatile with more than 200 species grown in various parts of the world. While red and black raspberries are the most popular varieties, the fruit can also appear as orange, yellow or purple. People are heavy consumers of this popular berry. Berries are enjoyed fresh and are commonly used to make delicious jams, pies, cakes and other tasty foods. In the wild, raspberries are a staple food for over 150 bird species, black bears, rodents and other mammals. In addition to being a food source, raspberry plants serve as convenient cover from predators.