This unusual climbing cactus is Pereskia aculeata. It is commonly called Barbados Gooseberry, Lemon Vine or Leaf Cactus. Although it may look more like a thorny shrub or scrambling vine than a cactus, it belongs to the cactus family, Cactaceae.

Unlike most familiar cacti, Pereskia aculeata has broad, ordinary-looking green leaves. These leafy cacti represent an early branch of cactus evolution and help us imagine what the ancestors of today’s leafless, water-storing cacti may have looked like.

The plant grows as a woody, scrambling shrub or vine. Its long, flexible stems climb through surrounding vegetation and may reach considerable lengths when they find trees or structures for support.

At the base of the leaves are specialized cactus structures called areoles. From these arise clusters of sharp spines, some of which become hooked and help the plant grip nearby branches as it climbs. The species name aculeata means armed with prickles or spines.

The leaves are smooth, fleshy and oval, with pointed tips. They can store some moisture, but the plant also retains the broad leaf surface needed for ordinary photosynthesis. This combination of leaves, succulent stems and cactus areoles makes the species especially interesting botanically.

The flowers are usually white, cream or pale yellow, sometimes with a pinkish tint. They have numerous petals and a dense cluster of yellow stamens in the center, giving them the appearance of small wild roses.

The flowers may be pleasantly fragrant and attract bees and other insects. Several blossoms can open together in branching clusters, producing a surprisingly delicate display on such a heavily armed plant.

After pollination, the plant develops small rounded or pear-shaped fruits. These begin green and ripen to yellow or orange. Their leafy outer structures may remain attached around the fruit, creating a slightly unusual, layered appearance.

The ripe fruits are edible and have been used in drinks, preserves and local dishes in parts of tropical America. The leaves are also eaten as a vegetable in some regions, particularly in Brazil, where the plant is known as ora-pro-nóbis. Visitors should nevertheless never sample a plant in a botanical collection without permission and positive identification.

Kew currently accepts Pereskia aculeata as the scientific name and records its native range from Panama into tropical South America. It grows mainly in seasonally dry tropical habitats, although it has been introduced to many other warm regions.

Outside its native range, the plant can become invasive. Its climbing stems may form dense, thorny masses over trees and shrubs, while birds and other animals can disperse its fruits and seeds.

Pereskia aculeata is therefore a cactus that challenges our expectations. It has leaves instead of a leafless green stem, climbs like a vine, flowers like a rose and produces soft, colorful fruit.

When presenting it to a group, the most useful feature to point out is the areole. Those small structures bearing clusters of spines confirm that, despite its leafy appearance, this is a true cactus.