Generally speaking, in the plant world, one flower will produce one fruit. Partridgeberry (Mitchella repens) is one of the two exceptions. Partridgeberry, along with only one other species of plant native to Japan, are sometimes referred to as “twinberries” because each fruit is the product of two adjacent flowers. In June, pairs of fuzzy four-petaled white or pink flowers bloom at the end of each stem. Each pair of flowers is comprised of one with a tall pistil and short stamens, and one with a short pistil and long stamens. The result of this opposite arrangement is that the flower with the tall pistil is almost always fertilized by the other with tall stamens, while the flower with the short pistil is fertilized by the short stamens, essentially preventing self-fertilization within any one flower. The ovaries of these paired blossoms are fused, forming a single globular red berry with two blossom ends, instead of one, which occurs in most other berries.
Creeping along close to the ground, partridgeberries put down new roots at various places along their horizontally extending stems. As a result, they form trailing evergreen mats that can be seen any time of year in damp forests. The leaves are approximately 1/2 an inch long, shiny, egg shaped with light colored veins, and oppositely arranged along the stem.
The red berries, which ripen in late summer but often persist through the winter, provide food for birds, such as grouse, quail and wild turkeys, especially when other food becomes scarce. Partridgeberries are also edible for humans, but because they are rarely available in any large quantity, they are often no more than a small woodland snack.