The potato plant, Solanum tuberosum, is a member of the nightshade family, Solanaceae, alongside crops like tomatoes and peppers. While the potato tuber is a foundational global food source, the plant’s above-ground structures, especially the flower, are often overlooked. The flower represents the reproductive phase, preceding the development of true potato seeds. Despite widespread cultivation, many people who consume potatoes have never observed its bloom in a field.
The Distinctive Anatomy of the Potato Flower
The potato flower typically appears in clusters at the tips of the stems, forming a branched structure known as a cyme. Each individual flower is relatively small, measuring less than one inch across, but possesses a distinct, star-like shape. This characteristic appearance is created by the corolla, which consists of five petals that are fused together at the base and spread outward into a flat, often five-lobed surface.
The reproductive structure confirms the plant’s membership in the nightshade family. Five stamens, the male organs, are typically joined along their edges. This fusion creates a unique, cone-like structure that encircles the central pistil. The anthers, located on the stamens, are often bright yellow, contrasting sharply with the color of the petals.
The pistil, the female organ, is situated inside the cone formed by the anthers, including the ovary, style, and stigma. This arrangement is well-suited for self-pollination, where pollen is released directly onto the stigma. Once successfully pollinated, the flower detaches easily at a joint on the stem, allowing the potato fruit to develop.
Cultivar Variations in Color and Flowering Habits
The color of the potato flower depends entirely on the specific variety, or cultivar, being grown. Flowers display hues including pure white, shades of pink, lavender, and deep purple. For example, the popular Russet Burbank variety often produces a white or sparse white flower, while the Shepody variety may exhibit a purple bloom.
These differences in flower color are genetically determined and can offer growers a visual clue about the tubers developing underground. Cultivars are also highly variable in their tendency to flower and the abundance of those flowers. Many modern commercial varieties have been selectively bred to allocate most of their energy to developing large tubers rather than producing seeds.
This breeding focus often results in plants that flower less reliably or drop their blooms quickly, which is why many commercial potato fields may not appear covered in flowers. Environmental conditions, such as high temperatures or specific day lengths, can also suppress blooming. The variability in flowering is a direct result of decades of agricultural selection focused on maximizing the edible underground crop.
The Toxic Fruit That Follows Flowering
After the potato flower is pollinated and the petals drop, a small, round fruit begins to develop. This fruit is often called a potato berry or “seed ball” and resembles a miniature tomato or tomatillo, given the plant’s family relation. The berries are typically green or yellowish-green when mature and measure about half an inch in diameter.
This fruit is highly toxic and should never be consumed by humans or pets. Like other above-ground parts of the potato plant, the berries contain high concentrations of the toxic compound solanine, a glycoalkaloid. Ingesting the fruit can lead to serious gastrointestinal and neurological distress, including vomiting, diarrhea, and headaches.
The potato berry contains the plant’s true botanical seeds, which are primarily used by plant breeders to develop new varieties. For the average gardener or farmer, the presence of these small fruits confirms the plant successfully completed its sexual reproductive cycle. Home gardeners should remove and discard any potato berries that appear to eliminate the danger of accidental consumption.