The big trees usually have broad buttresses at the base to offer extra support. You may not see their crowns because the tangle of climbers up the trunk probably block the view. Beneath them, you can find small trees, and some of them are actually saplings of the forest giants. In the forest undergrowth, you can also find palms, as well as seedlings and small soft-tissued herbs of the forest floor.

Thus, the tropical rain forest greenery is multi-layered.

You may see plants - often ferns - riding high on a tree trunk or branch, up where the light is brighter in many places. These are called epiphytes. They are unable to survive in the darkness at ground level because they have no connection with the ground. They gather nutrients only from the rain and the debris that collects around the plant. That's why epiphytes do not grow to a large size.

There are climbing plants which range from slender soft-stemmed creepers to giant lianas. Some are as much as 30cm, thick and with many leafy branches spreading out among the tree tops. The rattan - spiny stemmed climbing plants - is among the common one to be found.

Strangling figs (Ficus spp), with stems that descend from a high branch of a host tree, and then divide, rejoin and thicken around the trunk, can be seen in a rain forest, too. The fig's leaves crowd out those of the host. Eventually, the host tree dies.

There are trees which flower and fruit every year; others only once in every four or more years. Some trees and climbers flower from the main stem rather than from the leafy branches-behaviour. They are called cauliflower.

Most rain forest trees replace their leaves progressively; some of the larger trees lose all their leaves once a year, and stand bare for a week or two before the new leaves sprout. Overall, however, the rain forest always maintains an evergreen appearance.

The undergrowth in virgin forest is relatively open in most places because of the year-round darkness on the forest floor. What makes the forest uncomfortable to walk through are the spiny stems of palm.

Buttresses, climbers, stranglers, palms, epiphytes, cauliflower - all in a multi-layered, evergreen ever-moist forest: this is Malaysia's tropical rain forest, Malaysia's "Green Heart".