Anredera cordifolia Madeira Vine
Madeira vine (Anredera cordifolia) is a noxious weed here in Australia.
It has naturalised along the east cost of Queensland and New South Wales, as well as southern Victoria and South Australia, Tasmania and the south-western corner of Western Australia.
Originally from sub-tropical South America it was likely introduced to Australia as a garden ornamental, its appeal is questionable but I’m biased as I have removed thousands of Madeira vine plants from local bushland.
Madeira vine is fast growing and can form a dense canopy which can out-compete and completely smother and kill native plants at all stages of growth.
It's an evergreen, mostly herbaceous, perennial twinning vine that can become somewhat woody with age. The stems can take on a reddish tinge when grow in full sunlight.
The leaves of Madeira vine are fleshy, glossy and succulent; they are ovate to heart-shaped and can reach a length of 6cm. The leaves are edible and taste similar to the related Ceylon or Malabar spinach (Basella albaandB. rubra) grown as a small-scale garden vegetable, albeit with a somewhat dirtier and more unpleasant taste.
Madeira vine flowers are small and white with prominent stamens. The flowers are borne on 10cm long sprays from December to April, the sprays are fluffy in appearance and it’s this appearance which is the reason for another common name for this plant, lamb's tails.
The plant apparently is able to set seed but I have never witnessed this personally, most of the time the flowers appear to atrophy and fall off, if it does set seed here they must be very small.
Each plant has a cluster of underground tuberous rhizomes at its base which can grow to about 10cm in length, they are white inside with a rough, brown skin. Any tubers left in the ground after the removal of the vine can produce new shoots.
Madeira vine also produces aerial tubers at each node of older leaves. They are similar in appearance to the underground tubers but are smaller and more rounded rather than elongated and are even more rough and bumpy in appearance. The aerial tubers make control of this weed difficult as the aerial tubers are easily dislodged when unwinding the vines from engulfed native plants and every tuber once it has fallen into the moist forest leaf litter can produce a new plant. The tubers are edible but hard to peel due to their rugged skin and not really worth the effort in my opinion.
Madeira vine also roots easily from broken pieces of stem so all parts of the plant need to be disposed of in a sealed bag in the trash so it doesn’t regrow. Care should be taken to pick up and dispose of as many dislodged tubers as possible and to fully dig up the all of the larger underground tubers.
Areas that have been cleared of Madeira vine should be revisited in about 2 months to remove regrowth from fallen tubers; it’s likely that this process will have to be repeated many times to fully clear the area. Regrowth will be quicker during rainy weather.
An alternative, possibly effective method of control is to leave the vine in the ground but partially scrape the stem the vines (about 20% of the diameter of the stem) and apply glyphosate herbicide. In theory this should allow the herbicide to be trans-located and kill both the aerial and underground tubers while they are still attached to the plant. Vines left on native plants should eventually rot away if treated this way.
Biological controls for Madeira vine are currently being developed.Plectonycha correntina, a species of leaf-beetle native to where Madeira vine naturally occurs and which feeds exclusively on Bassellaceae family members (of which Madeira vine belongs to and there are no native Australian members) was released in 2011. Although this beetle will not be able to fully eradicate Madeira vine, results from green house trials have proved promising and no doubt its release will help to reduce the vigour and slow down the spread of Madeira vine. Malabar spinach (B. albaandB. rubra) grown as a garden vegetable near Madeira vine infestations will likely be effected by this release, although Malabar spinach is a vigorous plant and shouldn’t be too badly damaged as this beetle prefers to feed on Madeira vine.