Vascular – Exotic
Dicotyledonous Herbs other than Composites
Giant rhubarb-like herb, dying back to the large creeping stems over winter, with huge prickly leaves up to 2.5 m tall and large sausage-like flower spikes up to 1 m tall with tiny flowers and fruit covering the spike.
Very scattered throughout New Zealand, but commonest in high rainfall areas, e.g. South Taranaki, Westland
Margins of wetlands, damp cliffs and banks, often in light shade.
Giant, clump-forming, gynomonoecious, summergreen herb, with short, stout, horizontal rhizomes. Winter resting buds massive, to about 25cm long. Lvs to about 2.5 m high, rhubarb-like, but rough to the touch. Petiole to 1m long, studded with conic, short, often reddish, prickles. Inflorescence spike-like and up to 1 m long, with very small flowers. small round orange fruit 1.5-2 mm long.
Very identifiable plant. Some specimens in cultivation have been called G. manicata, perhaps in error but perhaps to avoid the prohibition on growing G. tinctoria. These always have a much more lax flowering spike. But otherwise are very similar dimensions to G. manicata.
October and November
Perennial. Gynomonoecious, i.e. has female and hermaphrodite flowers on the same plant. Reproduces by seed, and massive rhizomes. Huge amounts of seed with high viability is produced. No information on seed longevity. Seed spread by birds and water, rhizomes by deliberate plantings, soil movement.
Chile to Colombia in the Andes
Reason for introduction
Can be controlled manually, mechanically or herbicidally depending on situation.
Extremely tolerant of salt, wide variety of soil conditions, very wet swampy sites to dry banks.
gunnera: Named after Bishop Gunner, a Swedish botanist
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Webb et al., (1988).
References and further reading
Webb, C.J.; Sykes, W.R.; Garnock-Jones, P.J. (1988). Flora of New Zealand Volume 4: Naturalised pteridophytes, gymnosperms, dicotyledons. Botany Division, DSIR, Christchurch.
Popay et al (2010). An illustrated guide to common weeds of New Zealand, third edition. NZ Plant Protection Society Inc, 416pp.
Williams, PA; Ogle, CC, Timmins, SM; La Cock, G; Clarkson, J (2005). Chilean rhubarb (Gunnera tinctoria); biology, ecology and conservation impacts in New Zealand.
DOC Research & Development Series no.210. Dept of Conservation, Wellington.