Temperate and tropical rainforest plants is a very broad topic and one about which volumes of books has been published. There are still volumes more to be published, because scientists are still trying to catalogue them. Once catalogued, and that will take decades if not centuries, then comes the major task of trying to understand them. How do they live and survive, plant interactions are often complex and not as apparent as with animals. What are their genetics? What are their potential uses?
Rainforests have been estimated to contain over 90% of the plant species found on Planet Earth. Many are minute, being literally microscopic and some can be huge, covering thousands of acres and weighing several tons. They are often hidden. One mushroom was just discovered living in the rainforest in Oregon, spreading out over 2200 acres of a national park and estimated at over 2000 year old, but hidden below the soil. Silent giants can be and are hidden in the rainforests of the world.
That mushroom was beneath the rainforest floor and is suspected of killing some trees, but is also decomposing and adding essential nutrients required by other plants. Even the trees it may kill are essential to its survival, for food and shade, so it can’t kill too fast or many. It may also be helping those trees by only removing the weak and sick ones, giving the young trees a place to grow and decreasing the spread of disease. It destroys one but helps the other, and which function has the most effect, or are they equal? Complex relationships!
Other rainforest plants include over 10,000 species of ferns, those primitive forms of plant life that evolved over 600 million years ago and created the coals beds and oil that we use today. Many of these ferns still exist in the rainforest and are now used as house plants. That is also true of thousands of types of orchids, bromilliads, antheriums, philodendrons and ornamental flowers that many take for granted. The common ficus, those little office trees, become towering giants in the rainforest.
The plants of temperate and tropical rainforests have other uses besides just beauty. Many exotic woods originate in the rainforests, but need to be cultivated rather than harvested. Some foods, such as passion-fruit and vanilla were first discovered as rainforest canopy plants. Medicines are still being discovered in the rainforests, potential cures even for AIDS and the common cold.
Plants of the tropical and temperate rainforests, there are millions. Their value is still being calculated and may never be truly known.