Rainforest Plants

There is a fantastic variety of rain forest plant life. A typical 10km square area contains 1,500 kinds of flowering plants and 750 tree species. These plants form a system of layers. The top layer consists of giant trees up to 75 metres tall that tower over the rest of the forest.

Canopy Trees, 20 to 30 metres tall, form the next layer. Shrubs and young trees make up the under layer, whilst the last layer is the forest floor itself. Ferns, herbs and seedlings that need little sunlight for growth are found in this bottom layer.

Small plants called epiphytes that need more sunlight attach themselves to the trunks and branches of the canopy trees. They never touch the ground, but their aerial roots absorb water from the moist air. Vines that have roots in the ground climb trees of the top layer to obtain the sunlight they require.

Most tropical rain forest plants are exotic and very beautiful. Orchids and bromeliads for example are found throughout the canopy and under-story. The flowering Rafflesia arnoldi which grows on the forest floor has the largest flower in the world measuring up to 1 metre across. Unfortunately it smells like rotting meat! However the odour attracts flies which carry out the necessary pollination.

The huge top layer trees are also quite strange. Many of them have huge base fins known as buttresses, which help support them in the poor soil, and prevent them being blown over by the high winds that can accompany the monsoon. Other trees send their roots down from their branches to provide extra support. Many trees have also evolved protection from leaf eating insects and animals, as they produce disagreeable chemicals in their leaves making them unpalatable. Others grow spines on their trunks and branches making it hard for animals to reach their leaves. Some have hollows in their branches for ants to nest in, and they return the favour by attacking those insects and vines that can harm the tree.

Many rainforest plants are very useful. Food such as pineapple, banana, grapefruit, avocado and coconut originated there, as did many spices like chocolate, vanilla, nutmeg, cinnamon, black pepper, ginger and paprika. Chicle, (chewing gum) as well as bamboo and balsa wood also come from the rainforest.

• The Physical Environment
• Rainforest Plants
• Rainforest Animals
• Peoples of the Rainforest
• Rainforest Destruction
• What can be done to save the Rainforests?
• The Consequences of Tropical Rainforest Destruction
• Suggested Further Reading