Vitória Régia: Giant Waterlilly in the Amazon

These amazing plants produce gigantic leaves to cover as much surface area as they can, competing for precious light. Click the picture to see it in you tube. From the BBC. 

The Legend

In olden times, on the margins of the majestic Amazon river, the beautiful young women of an indian tribe gathered to sing and dream of life. They stayed for long hours staring at the beauty of the white moon, and the mystery of the stars, dreaming of being one of them.

As the aroma of the tropical night pulled at their dreams, the moon laid an intense light on the waters, making Naia, the youngest of the tribe and a dreamer, climb a tree to try to touch the moon. She didn't succeed. The next day, she and her friends climbed the distant hills to feel with their hands the smoothness of the moon, but again they failed. When they arrived there, the moon was so high that all of them returned to the longhouse feeling disappointed and sad. They believed that if they could touch the moon, or even the stars, they would transform themselves into one of them.

The following night, Naia left the longhouse hoping to fulfill her dream. She took the river trails to stare at the river's waters. There was the full moon, resplendent, immense, quietly reflecting its image on the water's surface. Naia, in her innocence, thought the moon had come to bathe itself in the river and allow her to touch it. Naia dove into the deep waters and there disappeared forever.

The moon, feeling pity for the young lost life, transformed Naia into a giant flower - the Vitória Régia - with an inebriating perfume and petals that spread on the water to receive the full light of the moon.

by Rosa Clement

The Rubber Tree

Natural Rubber Trees

Natural rubber comes from the Havea brasiliensis tree, which grows in tropical regions. They typically reach 20-30 metres in height on rubber plantations, and are able to produce commercial quantities of latex at about 7 years of age, depending on climate and location. Economical life span of a rubber tree is between 10 to 20 years, but may extend past 25 years in the hands of a skilled tapper and bark consumption.
It should be noted that latex is different to tree sap.

Dry Rubber Production

Tapping Rubber Trees

Havea trees are not tapped any more often than once per day, with 2 or 3 days being the norm. In countries such as Thailand, tapping usually takes place in the early hours of the morning, prior to dawn due to the high day time temperatures and the protective clothing worn to protect against snakes etc. Also flow rates are increased due to higher turgor pressures at these times.
A tapper uses a sharp hook shaped knife to shave a thin layer of fresh bark from the tree. This exposes the latex vesicles. The cut is typically done at 25-30° to the horizontal, as this exposes the maximum number of vesicles. The same incision is re-opened the next time (typically the next day) by shaving off a small amount of bark. Virgin bark is exposed first working around in panels. The same area may be exploited again after about 7 years.
AZoM - Metals, ceramics, polymers and composites - Tapping a rubber tree using angular, semi-spiral incisions.
Figure 1. Tapping a rubber tree using angular, semi-spiral incisions.
The thickness of the layer is important as too thick a slice will damage the tree and reduce its productivity and life, while too thin a slice will not produce sufficient latex. Bark is removed in a localised area for a period of time, and then a new area is tapped allowing the tree to repair itself.
The latex runs down and is collected in a cup. Each tree usually produces about half a cup of latex per day and is collected later in the day. Latex will flow for approximately 1 to 3 hours after which time the vesicles become plugged with coagulum.

Processing of Natural Rubber

Processing of natural rubber involves the addition of a dilute acid such as formic acid. The coagulated rubber is then rolled to remove excess water.
AZoM - Metals, ceramics, polymers and composites - Rolling the latex into thin sheets.
Figure 2. Rolling the latex into thin sheets.
Then a final rolling is performed using a textured roller and the resultant rubber sheet is dried. Following this, the rubber is ready for export of further processing. This type of natural rubber accounts for about 90% of natural rubber production.
AZoM - Metals, ceramics, polymers and composites - Final rolling of the latex sheets using a textured roller.
Figure 3. Final rolling of the latex sheets using a textured roller.
AZoM - Metals, ceramics, polymers and composites - The dried sheet of latex.
Figure 4. The dried sheet of latex.

Natural Rubber Production

Natural rubber is used in a pure form in some applications. In this case, the latex tapped from trees is concentrated using centriguges, removing water and proteinaceous materials. It is then preserved using a chemical such as ammonia.

Applications of Natural Rubber

The natural rubber is used for making products such as:
·         Glue
·         Tyres
·         Toys
·         Shoes
·         Condoms
·         Gloves
·         Catheters
·         Balloons
·         Some medical tubing
·         Elastic thread
At the end of a rubber trees’ useful life, the wood is used to make furniture and souvenirs.