'Loathsome' wild vine appears in Rangitikei

Forest and Bird, Issue 292, 1 May 1999, Page 12

'Loathsome' wild vine appears in Rangitikei

DoC, Wanganui

—Jo Priestley,

new weed threat has appeared mysteriously in a remote section of Rangitikei in the central North Island. White bryony Bryonia cretica ssp. dioica has not been found anywhere else in New Zealand, and its discovery in and around Makino Scenic Reserve in the middle reaches of the Rangitikei River is a worrying new record. It is mentioned in Culpeper’s Complete Herbal (17th century) as having berries ‘of a very loathesome taste, provoking vomit’ and a root with ‘a sharp, bitter, loathesome taste’. It resembles a cucumber plant, with masses of cream flowers over summer. It is fast-growing, but

dies back in the autumn to a massive perennial tuber. The plant produces an abundance of small yellow to red berries, so its seed is probably dispersed by birds. A weed expert from the Wanganui Conservancy of the Department of Conservation, Graeme La Cock, says white bryony is not known as a garden plant in New Zealand, and it is difficult to explain how it ended up in such an out-of-the-way place. ‘It can be very poisonous, and even cattle won't eat it, he says. White bryony was first collected in 1991 from Makino, where there were about 20 plants. Reports from local farmers indicate it was near the reserve some 20 years before

this, though. A survey last year revealed isolated plants along a three-kilometre stretch of the Rangitikei River. ‘Exotic vines have a history of being among the most damaging invaders of our forests, according to Graeme La Cock. ‘Quite frankly, the last thing we need is another old man’s beard.’ DoC staff are still experimenting to find the most effective way of killing the vine and more importantly its massive tuber, as the tuber has a nasty habit of resprouting after the vine has died. The success of current control work will become obvious next spring, when the plant is

due to resprout.