The bristly texture on the surface of a strawberry often leads people to wonder if the fruit has hair. While these small structures may appear like fine hairs or seeds, their botanical identity is complex. The answer lies in the plant’s anatomy, which classifies the strawberry differently than most typical fruits.
The Structures That Look Like Hair
The small, speckled bumps embedded across the surface of a strawberry are not hairs; they are technically the plant’s true fruits. These structures are called achenes, and each one is a dry, single-seeded fruit that does not open to release the seed. A typical medium-sized strawberry contains approximately 200 achenes, giving the fruit its characteristic dimpled appearance.
The seed is contained inside the hard outer layer of the achene, which is often mistaken for the seed itself. When eating a strawberry, a person consumes hundreds of these separate, miniature fruits along with the surrounding fleshy tissue. The achene’s outer shell protects the microscopic embryo inside, ensuring the plant’s reproductive material can survive digestion and be dispersed.
Why Strawberry Seeds Are On The Outside
The external location of the achenes is explained by the strawberry’s unique classification as an “accessory fruit,” also known as a pseudocarp. In most plants, the fruit develops solely from the flower’s ovary, and the seeds are contained inside the ripened ovary wall. However, the fleshy, edible red part of the strawberry is not the ripened ovary.
Instead, the sweet, juicy portion is the greatly enlarged receptacle, which is the part of the flower stalk that holds the floral organs. After pollination, the receptacle swells and becomes the main body of the strawberry. The true fruits—the achenes—remain on the surface of this swollen receptacle, placing the seeds on the outside. This anatomical difference means that the part of the strawberry consumed is stem tissue, while the structures on the outside are the botanical fruits.
The Role of Tiny Plant Hairs (Trichomes)
While the visible bumps are achenes, the strawberry plant does possess structures that are the botanical equivalent of hairs, known as trichomes. These are small, hair-like outgrowths that arise from the plant’s epidermis. Trichomes are most commonly found on the leaves, stems, and the calyx, which is the small green cap at the top of the fruit.
Trichomes are categorized as either glandular or non-glandular. Non-glandular trichomes are simple, long structures that act as a physical barrier against small pests and help reduce water loss. Glandular trichomes are smaller and secrete chemical substances that deter herbivores. These true plant hairs are too fine to be the primary structures noticed on the strawberry’s red surface, which are overwhelmingly the achenes.