Gunnera manicata, commonly known as Giant Rhubarb, is a semi-evergreen perennial herb, and may die back in colder climates. It is native to the Serra do Mar mountains of southeastern Brazil, where it thrives in the damp, high-altitude regions. The plant can reach up to 2.5 meters (8 feet) in height and can spread 4 meters (13 feet) or more. The leaves are its most striking feature, often exceeding 120 cm (4 feet) in diameter, with a mature plant’s overall spread reaching 3 m × 3 m (10 ft × 10 ft). These leaves are green and robust, with a spiny underside and stalk. In early summer, Gunnera manicata produces inconspicuous red-green flowers in conical branched panicles, followed by small, spherical fruit, though it is primarily grown for its impressive foliage.

Gunnera manicata is valued for its dramatic architectural form and is often used as a focal point in large-scale plantings or near garden ponds. It requires a sheltered position with part shade, high amounts of water, and prefers soils with medium drainage to replicate its native damp habitat. While it dislikes winter cold and wet, it can tolerate some frost if the crown is protected. Due to its size and water needs, it is not recommended for small gardens. In regions where it is not invasive, it can be an impressive addition to the landscape, but its potential for invasiveness should be carefully considered.CC BY-SA 4.0