chocolate tree, or Theobroma
Cacao originates in South America.
It is a "lower rainforest canopy" plant, and thrives in damp warm
conditions with partial shade.
The plant germinates from a cocoa bean, which quickly spouts and
splits, producing a stem that produces new single-stalked leaves at its
apex as it grows. Leaves are initially a translucent red, hanging
down vertically on the ends of horizontal stalks. Hanging
vertically allows the limp growing leaf to expand quickly, with water
more easily able to reach all parts of the expanding leaf,
without the shape needing support. The damp growing leaf and its stalk
expand from a few millimetres in length to the size of an adult
human hand in
just a few
days, then harden and turn a medium dark green.
Adult Leaves are paper-thin and do not hold a great deal of moisture.
This makes them difficult to digest for insects, and their fast
growth-phase means that the initial window of vulnerability is small.
stems also have fine hairs to make it more difficult for insects to
travel over the plant. Once the
leaf has attained maturity, a muscle-like swelling at the base of the
stem and the base of the leaf raise it up to face the light.
The thin, dry leaves are vulnerable to dehydration and
overheating, and can easily turn brown around the edges, and ultimately
drop. These fallen leaves can take a surprisingly long time to
biodegrade, and can remain on the ground under the plant, propped up
at an angle by the attached stalk, for many months. a spread of this
leaf litter allows water through to the ground while depriving any
seedlings of light near the plant's base.
Once the single stalk has reached a certain size it will produce a
of new stems, each of which then grows like the original.
Until this point, the plant may look like "a straight stick with
leaves". Crowning can be induced early (to produce a tree with more
by deliberately damaging the stem tip, although this risks damaging the
The stem also also has soft green thin flexible spikes around the
stems. In an
adult tree, some of these should change into flowers, resulting in
large sweet-tasting yellow or orange seed-pods, containing large bitter
When roasted and processed, these brown seeds (the cocoa beans) are the
base material for chocolate.
Amongst its other unusual properties, the lipid obtained from cocoa
beans (cocoa butter) is supposed to have the highest melting point of
any raw vegetable fat, and is supposed to be the only plant oil or fat
up to almost human body temperature. This melting point is
part of why chocolate dissolves so well in the mouth.
copyright © E. Baird, 2007