Sekamallit

Sekamallit, also known as "sleeping beauties" or "sleeping grass," are a group of plants that exhibit a unique survival strategy during periods of drought or cold. This phenomenon is primarily observed in certain species within the genus Oxalis, which is part of the wood sorrel family (Oxalidaceae). The term "sekamallit" is Finnish and translates to "sleeping beauties," referring to the plants' ability to fold their leaves and appear to "sleep" during unfavorable conditions.

The most well-known species exhibiting this behavior is Oxalis triangularis, commonly known as purple shamrock or iron cross. During the day, the leaves of these plants are open and flat, but as night falls or when the plant is stressed, the leaves fold up and the leaflets curl inward, resembling a closed umbrella. This response is triggered by changes in light, temperature, or humidity. The folding mechanism is facilitated by specialized cells called pulvini, which are located at the base of the leaf petioles. These cells can rapidly lose or gain turgor pressure, causing the leaves to move.

The primary purpose of this behavior is to conserve water and protect the plant from environmental stress. By folding their leaves, sekamallit reduce the surface area exposed to the elements, minimizing water loss through transpiration. Additionally, the folded position can help shield the delicate leaf tissues from excessive sunlight, cold, or physical damage.

Sekamallit are popular as ornamental plants due to their unique appearance and interesting behavior. They are relatively easy to care for and can thrive in a variety of conditions, making them a favorite among gardeners and plant enthusiasts. The plants are often grown indoors as houseplants or outdoors in gardens, where they can add a touch of whimsy and intrigue.