Hortus Botanicus Leiden, Netherlands

Common name: Mammoetblad, Reuzenrabarber, Giant rhubarb

Family: Gunneraceae (Gunnera)

Distribution: Zuid-Brazilië, Colombia

Hardiness: Zone 07

Life form: Perennial

Comments: Giant rhubarb lives up to its name: in summer the huge umbrella-shaped leaves can be seen from the other side of the canal. This species is native to southern Brazil and Colombia. In our climate the plant is hardy as long as it is covered well. In parts of Europe with even milder winters, this spectacular garden plant has started to naturalise and is considered invasive. Gunneras need a damp location: marshy, but not in water. It is a special genus that has nothing to do with rhubarb: Gunnera is the only genus in a separate family. Its flowers form panicles of up to 80 cm long, with small male and female flowers. The panicles are situated among the leaves and slowly take on an orange colour. We sometimes give away panicles for huge ornamental flower arrangements, for instance for floats for parades at flower festivals. Thick gloves are required if one wants to use the plant, as there are thick spines on the stems of the panicles, the leaf stems and the lower side of the leaves.