The first thing to know about strawberries is they are not berries in the botanical sense. Berries are fruits like blueberries, grapes, citrus fruits, and even tomatoes and cucumbers. We think of the big, red fleshy part of strawberries as the fruit and the little spots covering it as the seeds. In reality, the little spots on strawberries are not seeds, and the fleshy part we eat is not the fruit, at least in the botanical sense.
Strawberries are classified as aggregate fruits. The main bulk of the strawberry is the receptacle. The receptacle is covered with a bunch of little aggregate fruits. Those are all the little spots. So, the strawberry is a bunch of tiny fruits clustered together on a swollen receptacle. Botanists call these little fruitlets achenes and the receptacle, which forms part of the fruit is called accessory tissue. Since the fleshy part of the fruit is the receptacle and doesn’t come from the ovaries of the flower, botanists call this formation a “false fruit” or pseudocarp.
Those little fruits on the outside are not just seeds, but they do contain seeds!
Collecting seeds from strawberries is best done by allowing the fruits to dry in a warm, dry, sunny place. Then, the dried fruits can be worked between your fingers so that the little dry achenes can fall off. They can then be further dried for several more days before planting or storing.
While raspberries and blackberries are also aggregate fruits, their formation is different from the strawberry. The small fruits of raspberries are called drupelets or drupes. They are held together by interlocking hairs and all the small aggregate fruits separate from the receptacle as a unit when picked.
