Many common vegetables produce flowers that are often overlooked in the garden, as growers focus on the fruit, root, or leaf that follows. These blossoms are a necessary step in the plant’s reproductive cycle, leading to the harvestable portion. A surprising number of these vegetable plants display flowers in rich hues of lavender, violet, and deep purple. This color is frequently the result of plant pigments known as anthocyanins, which are compounds also responsible for the color in many red, blue, and purple fruits.
Purple Blooms on Nightshade Vegetables
The Solanaceae family, commonly called the Nightshades, includes several widely consumed vegetables that feature striking purple blossoms. One of the most recognizable examples is the eggplant, or aubergine, which produces beautiful star-shaped flowers that are typically a shade of light to deep purple. These flowers are the precursor to the large, glossy fruit. The anthocyanins that color the eggplant fruit are also present in the delicate flower petals.
The potato plant, another member of the Nightshade family, also produces flowers that range from white and pink to various shades of purple. These flowers appear at the end of the stem, indicating the plant is preparing to produce tubers underground. Unlike the eggplant, where the flower leads directly to the edible fruit, the potato flower is separate from the underground tuber harvested for food.
While the potato tuber is safe to eat, other parts of the plant, including the flowers, leaves, and green parts of the tuber, contain higher concentrations of toxic compounds known as glycoalkaloids. This contrast highlights a difference within the Nightshade family, as the eggplant flower matures into a safe, edible fruit, but the flower and fruit of the potato are not consumed. The purple coloration across this family serves the function of attracting pollinators to ensure fruit and seed production.
Legumes That Display Purple Flowers
A separate group of vegetables with purple flowers belongs to the Fabaceae family, known as the legumes, which includes beans and peas. Many varieties, such as certain pole beans and the hyacinth bean (Lablab purpureus), develop flowers in shades of lavender and violet. These blossoms have a distinct, asymmetrical structure known as papilionaceous, or “butterfly-like.”
This specific structure includes a large upper petal called the standard, two side petals called wings, and two lower petals fused together to form a keel. This design is specialized for pollination, often requiring an insect to land on the wings and keel to trigger the release of pollen. Once pollinated, the flower gives way to the formation of the seed pod, which is the part of the plant consumed as a vegetable.
The legume flower’s purple color and specialized shape are distinct from the radial structure seen in the Nightshade blossoms. This difference reflects the varied evolutionary strategies plants use to ensure reproduction. In legumes, the purple flower is a transient, yet necessary, stage leading directly to the edible seeds and pods that follow.
When the Flower Itself Is the Edible Part
In some instances, the purple part of the vegetable we eat is either the flower itself or an immature flower head. The globe artichoke, a thistle species, is a prime example where the edible portion is the tightly closed, immature flower bud. If the bud is not harvested and is allowed to mature, it opens into a large, thistle-like flower with prominent purple florets.
The purple color in varieties of cauliflower and broccoli is also due to high concentrations of anthocyanins. These vegetables are harvested as compact, underdeveloped flowering heads, technically called inflorescences. While they are not the true, open flowers of the plant, their deep purple hue links them visually to the other purple blooms in the garden. This diversity shows that purple coloration can appear at multiple points in a vegetable plant’s life cycle, such as in a transient pollinator attractor or the edible, immature flower head.