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 or sub-reniform leaves typically long, not including the thick, succulent petiole which may be up to in length. The width of the leaf blade is typically , but on two occasions cultivated specimens (In Devon, England in 2011 and at Narrowwater, Ulster, Ireland in 1903) produced leaves fully 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.