Gunnera tinctoria may easily be confused with the closely related Brazilian species Gunnera manicata Linden ex Delchev. Very similar to look at, Gunnera manicata is somewhat larger than its Chilean relation and often forms a rather larger clump[, ].

Common Name: Gunnera

General Information

Gunnera tinctoria is a herbaceous, perennial plant forming a cluster of large leaves on long prickly petioles and looking rather like a giant rhubarb plant. Growing from a large, woody rootstock, the petioles can be 200cm or more tall in good conditions surmounted by a large, somewhat thorny leaf that can be 150cm or more wide. The plant spreads (usually quite slowly) by short rhizomes to form a large clump.
The plant is harvested from the wild for local use as a food, medicine and source of materials. A popular food in Chile, where it is known as 'nalcas', the plant is commonly harvested from the wild and often sold in local markets[]. The plant is widely grown as an ornamental in gardens, where it can be used as an effective ground cover.
Gunnera tinctoria is widely planted as an ornamental in gardens and parks. Especially in regions with moist climates and mild winters, the plant has escaped from cultivation and become naturalized to form dense monospecific stands that shade out other plants - large stands have been produced on the west coast of Ireland, southwest England, the west coast of Scotland, the Azores, the coast of California and New Zealand where dense local infestations are found on coastal cliffs. It can spread from rhizomes discarded from gardens and from seed disseminated by birds and is a threat to native vegetation. Its sale and further cultivation is now prohibited in Ireland and New Zealand where eradication programmes are underway[].

Known Hazards

None known

Botanical References

Range

S. America - central and southern Chile to southwest Argentina.

Habitat

Forest margins adjacent to wetland areas, stream-sides and, particularly, on bluffs and talus slopes[]. Moist soils by lakes and rivers of the Central Provinces[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	2.00 m
Pollinators	Bees, Wind
Cultivation Status	Ornamental, Wild

Cultivation Details

Gunnera tinctoria is fairly cold tolerant, especially if a thick mulch is applied to the rootstock whilst the plant is dormant. Unprotected, the roots will generally survive occasional temperatures falling as low as -10°c, somewhat lower with protection. The young growth in spring, however, can be damaged by late frosts[, ].
Requires a damp humus rich soil in a sunny position or semi-shade, sheltered from strong winds. Plants can be grown in quite coarse grass, which can be cut annually in the autumn[].
The top part of the inflorescence is male, the bottom is female and the middle is hermaphrodite.
A very ornamental plant with huge leaves, it forms a slowly spreading dense clump[].
The genus Gunnera is unique in the plant kingdom by acquiring nitrogen through symbiosis with the nitrogen-fixing cyanobacterium, Nostoc punctiforme. The structurally unique stem glands of Gunnera function as the conduit through which cyanobacteria infect the host. As the genus Nostoc is cosmopolitan and common, it is likely to be present in the wet habitats in which Gunnera grows[].
Members of this genus are rarely if ever troubled by browsing deer[].

Edible Uses

Young leaf stalks - peeled and cooked as a vegetable or eaten raw[, , , ]. Acid and refreshing[]. An agreeable, bitter-sweet, refreshing taste[, ].

Medicinal

The whole plant is rich in tannins and is used as an astringent[, ]. A decoction of the hard roots is used as a treatment for diarrhoea[].

The stem and the root are used as a treatment against pains in the uterus, as a haemostatic and an antiinflammatory[]

Agroforestry Uses:

Gunnera species have a high potential for use in the recovery of lands affected by erosion, given their condition as colonizing plants that are capable of fixing atmospheric nitrogen through symbiosis with the cyanobacterium Nostoc punctiform[].

Other Uses

A black dye is obtained from the root[]. Only a small amount of juice can be obtained from the hard root, but the dye is of very good quality and permanent[].

The root contains 9% tannin[, ].

Leaves are used as a roof covering[].

Propagation

Seed - best sown as soon as it is ripe in the autumn in a sandy mix in a cold frame. The seed can also be sown in a shady position in a greenhouse in the spring. Germination usually takes place within 2 - 8 weeks at 15°c. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts.
Division as new growth commences in the spring. The clumps can be planted out direct into their permanent positions.