More than half of the world's plants and animals live in tropical rainforests. In some sections of the rainforest, a 2 1/2-acre section may contain more than 750 types of trees and 1,500 species of plants. Deforestation of the tropical rainforest and illegal collecting of vulnerable plant species cause more plants to be added to the endangered or extinct species list each day.
More than 25,000 different types of orchids grow in rainforests, with more than 3,000 species of orchids growing in Borneo alone. Many of these plants are endangered or threatened. In the tropical rainforest, orchids usually grow as epiphytes, meaning the plants grow high in the trees, never touching the ground.
The plants get their start in the canopy 100 to 150 feet in the air after the seeds or spores get transported and dropped there by birds or wind. The plants grow by obtaining nutrients from the air, rainfall and compost on the tree branches.
Endangered orchids include the moth orchid and the Cooktown orchid, among others. Deforestation and illegal collecting of the plants contribute heavily to the growing list of endangered orchids.
More than 17 species of rafflesia, a smelly but fascinating flower, exist today in the rainforests of Southeast Asia. The plant is on the endangered list because it is a parasite that requires very specific hosts, which are found only in the same geographic areas.
The main host plants it prefers include the Tetrastigma, a member of the grape family. While the plant sports no leaves, roots or stems, the plant produces huge flowers, up to 3 ft. in diameter, after sucking nutrients and water from the host plant.
The reddish-brown flowers stink of rotting flesh. While the parasitic plant has no value as a crop, it plays a huge role in ecotourism, with thousands of people heading to Borneo each year to search for the blooms.
In the rainforest, understory plants tend to feature large leaves that soak up as much light as possible from what gets filtered down through the canopy. One such plant, triunia robusta, was thought to be extinct until recently.
Now on the endangered list, the small shrub, found in a small area in Queensland's rainforest, grows to 12 ft. high. It sports 6-inch leaves and long, fragrant flower spikes.
The tree produces a reddish fruit a little over 1 inch long that is eaten by birds and wildlife. The main threats to the plant include habitat destruction and illegal harvesting of the seeds and cuttings.