Strawberry

Strawberries come from small perennial plants of the genus Fragaria, whose 20 species range across the northern hemisphere. The plants are easy to grow and therefore are grown widely, from subarctic Finland to tropical Ecuador. The strawberry is unusual in bearing its “seeds” on the surface of the fleshy portion, not inside. The “seeds” are actually miniature dry fruits (achenes), similar to buckwheat and sunflower “seeds,” and the fleshy portion is the flower’s swollen base, not its ovary. During ripening, the cells of the strawberry interior enlarge and pull apart from each other. The berry is therefore filled with tiny air pockets, and its shape is maintained by the pressure of the cell contents pushing each cell onto its neighbors. When this pressure is released, by water loss from drying out or from freezing that punctures the cell walls, the structure weakens and the fruit becomes soft and mushy. Strawberries don’t improve once picked, so they must be picked ripe. Thanks to their thin skin and fragile structure, they only last a few days, even in cold storage.