Ripogonum scandens


Ripogonum scandens, is a common rainforest vine native to New Zealand. It can also grow in areas of swamp.
Supplejack is a climbing liana, that has hard but flexible stems. It starts its life as a sappy stem searching for a support. Once it finds a shrub or tree to cling onto, it grows upwards to access sunlight, where it then develops branches and leaves.
The supplejack flowers from December to February. It however bears clusters of red berries throughout the year.
During summer supplejack tips grow 5 centimetres a day, enabling the plant to climb high up into the canopy of the forest.

Taxonomy

In 1769, during explorer Lieutenant James Cook's first voyage of discovery, botanists Joseph Banks and Daniel Solander collected specimens of "supplejack" in New Zealand. The species was described in Solander's unpublished manuscript Primitiae Florae Novae Zelandiae and was illustrated by Sydney Parkinson. Cook again visited New Zealand in 1773 during his second voyage. While anchored at Dusky Bay in the South Island of New Zealand, he remarked in his journal:
During this voyage naturalist Johann Reinhold Forster, assisted by his son Georg Forster collected plant specimens, the elder Forster offering the following description in his journal:
In 1776, the Fosters published the genus Ripogonum in the second edition of their Characteres Generum Plantarum with Ripogonum scandens as the type species.

Species Description

The Supplejack vine is an evergreen, indigenous climbing vine. It climbs by coiling its stems around tree trunks and branches. When there I no supporting trees for the vines to climb up, the vines create a tangled mess on the forest floor, creating a dense knotted entanglement. In the first few years of establishment, the SuppleJack mirrors a small shrub, but in its later seasons the stems start to spiral around the supporting trees. In summer, when the conditions are right, the tips of the vines can grow up to 5 centimetres per day, giving ample opportunity for the vines to climb high into the canopy, suffocating trees in the fight for light. When the vines/ stems reach the sunlight at the top of the canopy, they begin to produce green leafy stems opposed to the brown woody stems; which begin to produce flowers and fruit. Flowering takes place during October till May granted the stem is in full light at the top of the canopy. Fruiting takes place throughout the year and the Supplejack will produce small red berries. The leaves are opposite, ovate and shiny. Male and female flowers are separate, female flowers produce the larger berries.

Traditional Māori uses

Traditionally supplejack was used by Māori to bind and pull objects. For example, the vine was used to tie firewood together and for towing small canoes.
Medicinally the supplejack root was boiled to make a drink to help a variety of conditions including rheumatism, fever, disability, bowel problems and skin diseases. The soft, fresh shoots of the vine can also be eaten raw or cooked as a vegetable.

Geographic Distribution and Habitat

Natural Global Range

New Zealand.

New Zealand Range

Found in the North and South islands of New Zealand as well as a few offshore islands including Stewart and Chatham Islands. R. scandens is mainly present is lowland and mountainous forests dominated by hardwood and podocarp throughout the North island. Ripogonum scandens is not found on the Three Kings Islands and on the Poor knights Islands. It occurs infrequently in the Hawke’s Bay only in old coastal forests. It is found at altitudes in the North Island of up to 900m in the Kapamahunga range. In the South Island of New Zealand Ripogonum scandens does not tend to seep into the forests, instead staying on the seaward facing ranges. Throughout Marlborough, Canterbury and Otago the occurrence of  R. scandens is found sparingly in relics of old forests and mainly found on peninsulas such as Kaikoura, Banks and Otago. The supplejack vine is abundant on the western coast of the South Island.

Habitat Preferences

Ripogonum scandens will inhabit a wide range of soil types such as red-brown loams, pumice, yellow brown and alluvial. It has also been known to be able to withstand swampy forests where the soil may be flooded periodically throughout the year and hooping of the roots above ground was observed in such soil conditions. Due to the climbing nature to the Supplejack they require strong branches and trucks to be able to climb up or else they remain a matted shrub on the forest floor.

Phenology

Shoots of differing lengths can be seen at all times during the year however they are most common during the springtime where the sun becomes stronger and they are able to photosynthesize more. Anthers become visible in December and through January. Once the anthers have been pollinated by either an insect or by wild pollination, the fruit takes approximately 12–15 months to fully ripen; the berries can be seen all year round. The seed germinates easily only if it doesn’t dry out.

Pathogens/Predators

Supplejack is very vulnerable to different types of birds and mammals that are known to eat the fruit and roots of supplejack. Kereru and blackbirds are two main birds that consume supplejack fruit. Kaka have also been known to have eaten supplejack berries. They fall victim to being over-consumed and being browsed too much leaving them stripped bare of either their leaves or a lot of their fruit. Over the years as the number of invasive species increase throughout New Zealand, this has started putting pressure on the plants survival rate and is now causing a decrease in how often the plant is occurring. A new climber specie related to supplejack called Geitonoplesium cymosum has somehow been brought over to New Zealand. This specie is very similar to the native supplejack but there is a threat that if this new specie continues to thrive and spread throughout New Zealand that it could out-compete supplejack. Wild pigs also have a negative impact on juvenile supplejack as they forage through the forest floor. While they are disturbing and consuming other plants, they are also uprooting growing supplejack. Deer and cattle also have the same negative impact on supplejack. These mammals graze on the seedlings and growing juvenile plants. Possums are another mammal in the New Zealand forests that eat the flesh of the supplejack fruit.
There is also a type of fungal specie that grows and covers supplejacks stems and leaves. This fungus is described as a sooty mould and is called Trichopeltheca asiatica. This fungus is common across New Zealand and since it tends to ‘smother’ the supplejack, this can greatly affect the plants ability to photosynthesize.
There are also some various species of moths from the order Lepidoptera that are found throughout New Zealand. One example is Ctenopseustis obliquana. Its larvae can be found in ripe fruit and it will also consume the stems, leaves and flowers of the supplejack.