Sunday, January 24, 2016

Giant Pepper Vine

Piper hederaceum

The storm the other night brought down this sprig from a giant pepper vine in Goomburra National Park.

 These fruits would have been preceded by tiny white female flowers, fertilised by the male flowers (which grow on the same plants as the females). I haven’t ever seen them (they tend to grow too far up in the rainforest canopy), but am told that they have a strong perfume.

A few giant pepper vines can still be found in the rainforest remnants on Toowoomba’s eastern escarpment. In earlier times they were so common in the Toowoomba district that they had a reputation for causing a major summer influx of white-headed pigeons, as they came to feed on the ripe fruits. This tells us something about how very much our local vegetation has changed since then. Anyone seen a white-headed pigeon lately?

Pepper vines have ornamental potential. They can be used both as small plants in hanging pots (in a shady spot where their broad “shade-leaves” would show to advantage) ....

or on a strong trellis or pergola of the sort that we more often see covered with Wisteria. Used the latter way, the pepper vine’s smaller “sun-leaves” would create a shady arbour, and the pretty summer fruits could be seen (together with the birds they would bring to the garden).

Curiously, the flowering stems produce even smaller leaves if they are going to flower. This lets us know when flowers and fruits are “in the pipeline”.

Giant pepper vines begin life as  root climbers, ascending the smooth surfaces of trees or rocks (or, potentially, a shady brick wall). This tendency to climb like ivy is the reason for its name “hederaceum”, a reference to the Latin word hedera, for “ivy”.
Here’s one whose high hopes are about to be dashed!

Stems of mature plants lose the clinging roots. However their nodes where leaves and roots were once attached, continue to be marked by distinctive rings. Pepper vine trunks are easy to distinguish from all those unidentifiable climbers that disappear up into the rainforest canopy.

The root-climbing habit gives giant pepper vine a tendency to cling rather closely to its supporting frame, clothing it in greenery and outlining its silhouette.
This dead tree has acquired a very quaint appearance! 

Fortunately for the beauty of the rainforest, the pepper vines avoid the smaller stems, so the host trees' own canopy is never overtaken by its pepper vines.

Stems which find nothing to cling to do not build high bulk, as with some climbers, but hang downwards in long festoons, sometimes almost reaching the ground. The effect, as they sway gently in the breeze, is cool and attractive.

Growers of the related Indian pepper of commerce (Piper negrum) say their plant restricts itself to whatever size of trellis it is given. Clearly ours would do the same. The festoons could be trimmed off if neatening is required. In the case of a pergola, they could be left to form curtain walls.

The Festoon Falls in the Bunya Mountains were named after a magnificent curtain of pepper vine, which enclosed the falls. My mother remembered it from her youth, but said it was destroyed in a cyclone “round the time of the war”. If you visit the site, you can see that the enormous trunk of the vine still grows at the top of the falls, but that the supporting trees from which the curtain used to hang have gone. The existing trees now support a few festoons...

... but it will be many years before the whole curtain will be restored.

Giant pepper vine is a frost tender plant. It grows moderately fast in Toowoomba’s climates, including its droughts, if it is in a shady site with well-mulched soil. Like all rainforest plants, however, it grows even faster if watered.

About Pepper
Worldwide, there are approximately 1,000 species of Piper.
Although the fruits and leaves of many of them are used in cooking, the best-known is , the source of the common pepper we buy in the supermarket. It is imported from Southern India, and the same plant is used to make white, black, green and red pepper.
White pepper is the hottest form, and consists of the naked seeds of green-picked fruits. They are separated from the flesh by soaking in a hessian sack for several weeks, causing them to ferment. Then they are trampled and washed until none of the fruit or skin remains on the seeds.
To make black pepper, the green fruits are spread on a cloth to dry in the sun. Their tangy black pepper flavour is developed by enzymes present in the fruits, as they dry and change colour.
The green-coloured pepper seeds we buy are “hot”, like the black, but not particularly flavoursome. The green colour is fixed by plunging them into boiling water for twenty minutes (to kill the enzymes), then sun-drying or freeze-drying them. Despite their inferior taste, there is a commercial demand for them, to enhance the appearance of mixes used in transparent pepper mills.
Left to ripen on the vine, pepper fruits turn yellow, then red. Dried ripe fruits are considered to have poor flavour and are rarely used, except in the same ornamental pepper mixtures. Their colour may be retained by freeze-drying, but  a commonly used commercial technique is to treat both red and green peppers with sulphur dioxide. While it preserves the bright colours, it has no appeal for those who would rather avoid unnecessary chemical additives in their food.
Pepper fruits can also be used fresh. The green ones are a staple of Thai cuisine. The red have a distinct fruity flavour.
Our native Piper hederaceum seeds less hot than Piper nigrum, but have a pleasant spicy flavour.