Gunnera

Gunnera tinctoria 2

Gunnera is a genus of flowering plants in the family Gunneraceae. The genus comprises about 40-50 species, which are native to various regions including South America, Africa, New Zealand, and Hawaii. The plants are known for their large leaves and are often referred to as "giant rhubarb," although they are not related to rhubarb.

Description

Gunnera species are perennial plants that can grow to impressive sizes. The leaves of some species, such as Gunnera manicata, can reach up to 3 meters in diameter. The plants have a distinctive appearance with their large, lobed leaves and thick, fleshy stems. The flowers are small and are typically arranged in dense, spike-like inflorescences.

Habitat

Gunnera species are typically found in moist, temperate regions. They thrive in environments with high humidity and ample water supply, such as riverbanks, wetlands, and rainforests. Some species are also adapted to grow in more arid conditions.

Symbiosis

One of the most interesting aspects of Gunnera is its symbiotic relationship with cyanobacteria of the genus Nostoc. The cyanobacteria live in specialized glands at the base of the leaves and fix atmospheric nitrogen, which benefits the plant. This relationship is unique among flowering plants and is a subject of scientific interest.

Cultivation

Gunnera is often cultivated as an ornamental plant in gardens and parks due to its dramatic foliage. It requires a lot of space and a suitable environment to thrive. The plant prefers a location with partial shade and rich, well-drained soil. It is also important to provide adequate water, especially during dry periods.

Species

Some notable species of Gunnera include:

• Gunnera manicata - Known as giant rhubarb, native to Brazil.
• Gunnera tinctoria - Known as Chilean rhubarb, native to southern Chile and Argentina.
• Gunnera insignis - Native to Central America.

Uses

While Gunnera is primarily grown for ornamental purposes, some species have been used in traditional medicine and as a food source. The stems of Gunnera tinctoria are edible and have been used in local cuisines.

Conservation

Several species of Gunnera are considered vulnerable due to habitat loss and over-collection. Conservation efforts are in place to protect these species and their natural habitats.

See also

• Gunneraceae
• Angiosperms
• Symbiosis
• Nitrogen fixation