Gunnera

Gunnera is the sole genus of herbaceous flowering plants in the family Gunneraceae, which contains 63 species. Some species have extremely large leaves. Species in the genus are variously native to Latin America, Australia, New Zealand, Papuasia, Hawaii, insular Southeast Asia, Africa, and Madagascar.[2] The stalks of many species are edible.[clarification needed]

The 40–50 species vary enormously in leaf size. The giant rhubarb, or Campos des Loges (Gunnera manicata), native to the Serra do Mar mountains of southeastern Brazil, is perhaps the largest species, with reniform or sub-reniform leaves typically 1.5 to 2.0 meters (4.9 to 6.6 ft) long, not including the thick, succulent petiole which may be up to 2.5 meters (8.2 feet) in length. The width of the leaf blade is typically 2.5 meters (8.2 feet), but on two occasions cultivated specimens (In Devon, England in 2011[3] and at Narrowwater, Ulster, Ireland[4] in 1903) produced leaves fully 3.3 meters (11 feet) in width, not far from the largest of all dicot leaves such as Victoria amazonica. The seeds germinate best in very moist, but not wet, conditions and temperatures of 22–29 °C.

Only slightly smaller is G. masafuerae of the Juan Fernandez Islands off the Chilean coast. They can have leaves up to 2.9 m (9 ft 6 in) in width on stout leaf stalks 1.5 m (4.9 ft) long and 11 cm (4.3 in) thick according to Skottsberg.[5] these leafstalks or petioles are the thickest of any dicot, and probably also the most massive. On nearby Isla Más Afuera, G. peltata frequently has an upright trunk to 5.5 m (18 ft) in height by 25–30 cm (9.8–11.8 in) thick, bearing leaves up to 2 m (6 ft 7 in) wide. The Hoja de Pantano (G. magnifica) of the Colombian Andes bears the largest leaf buds of any plant; up to 60 cm (2.0 ft) long and 40 cm (16 in) thick.[6] The succulent leaf stalks are up to 2.7 m (8 ft 10 in) long. The massive inflorescence of small, reddish flowers is up to 2.3 m (7 ft 7 in) long and weighs about 13 kg. Other giant Gunnera species are found throughout the Neotropics and Hawaii. Gunnera insignis is also known by the name “poor man’s umbrella” in Costa Rica.

Several small species are found in New Zealand, notably G. albocarpa, with leaves only 1–2 cm long, and also in South America, with G. magellanica having leaves 5–9 cm wide on stalks 8–15 cm long.