The plant with the largest leaf in the world is Raphia regalis, a species of Raffia Palm belonging to the palm tree family ARECACEAE. It has huge leaves that can reach a record breaking 25.11 m (82 ft) long by 3 m (10 ft) wide, which are longer than any other species of plant.
The leaves however are divided and are made up of around 180 seperate leaflets arranged either side of the leaf rachis (the central stem of the leaf).
The individual leaflets of Raphia regalis can reach up to 6.5 cm (2 1/2 inches) across at their widest point. The upper surface of each leaflet is green in color while the lower surface is waxy and appears grayish-white in color.
Normally the leaflets of plants in the genus Raphia have small spines along their margins and midrib, however Raphia regalis is a relative softy in comparison and the spines on its leaflets are sparse and tiny.
Like other Raphia species, the leaves of Raphia regalis remain attached to the plant once they have withered and died. This can cause plants in gardens to look straggly if the dead leaves are not pruned off.
Raphia regalis appears to have no stem (trunk) at first glance, but it actually has a short compact stem that is up to a metre in length. Most of the stem remains hidden underground causing the leaves to emerge from close to the ground.
These palms are becoming rarer in the wild due to habitat loss, because of thisRaphia regalis has been listed as vulnerable on the IUCN Red List of Threatened Species.
Raphia regalis can only be grown successfully in areas that receive a minimum temperature no less than 1.7 degrees Celsius (35 degrees Fahrenheit), USDA hardiness zone 10b.
Dry fibres collected from the central leaf stems of Raffia Palms provide a long, continuous strand that can be used as is as string to tie objects or weaved into baskets, hats or mats. The fibres are also made into a native textile exported under the name of rabanna. Roof coverings can be made from the inter-woven leaves of Raffia Palms.
The sap form Raffia Palms is rich in sugars and can be collected and fermented to create a traditional ethnic drink.