Mature HEVEA trees on rubber plantations are 20-30 meters high, with graceful upwards-extending branches and a relatively slim trunk. Such trees flower once a year, and after insect cross-pollination produce large fruits containing several thimble-sized seeds with hard outer coats. If satisfactorily germinated and planted within 2-3 weeks, seeds grow to produce seedling plants. Depending on conditions, the latter then take 5-10 years to reach 'maturity', which is defined as the stage when tapping can be started. In practice, this is the time when the trunk has about 500 mm circumference at 1 meters above ground level.
HEVEA trees convert inorganic nutrients from the soil, and carbon dioxide from the atmosphere, into organic carbohydrates which are then turned into rubber latex. The latter passes up the tree through millions of capillary vessels or tubes located in the soft outer bark.
At least once a year the leaves of the tree, which are the sites of carbohydrate formation, die and fall off in wintering, and new leaves are formed. During wintering, which lasts for sixteen weeks, the metabolism of the tree and the constitution of its are substantially affected. The yield is also reduced, and this, together with other climatic factors, accounts for marked seasonal variations in NR production in producing countries.
And we collect that leaves then use it as a material of art