In the Quaternary (2.5Ma to present), the herbaceous angiosperms increased their numbers, and the angiosperms dominated most ecosystems. Grasses also has became a major component of many natural systems.
The herbaceous, annual and ephemeral angiosperms were flourishing by 2.5 Ma in various parts of the world.
The flowering plants continued to diversify throughout the Quaternary to provide the huge range of plants in existence today. Grasses formed the grasslands which now support a huge range of fauna.
Of course, the older flora types continue to persist and flourish.
Cycads, Gnetales and gymnosperms are still seen growing in many forests, especially in the northern hemisphere. Ferns are very common, and there are many araucarian plants still in existence.
Many people have heard of the Wollemi Pine, and there is even a rhynia-type (Psilotum) still growing in Queensland, Australia! It is important to remember that evolution is an ongoing process. All plants, including those we label as "primitive" are still adjusting to the changing environments in which they find themselves.
Today the world's flora is extremely diverse but this diversity is at considerable risk from land clearing and other adverse human activities. Land clearing and urbanisation threaten many rare species and can add many more plants into this category over time. There are even cases of plants becoming extinct before they have been formally classified.
Global warming may have untold effects on the world's flora. However it should not be forgotten that this is not the first time the world has experienced warming. As you read through this tour, you would have become aware of repeated warming (and cooling) of the Earth's climate. While there are many species which are able to cope with the warming and increased carbon dioxide levels, there are others that will become extinct. While it is a pity to lose species as they become extinct, this is also a part of nature and is sometimes unavoidable. Perhaps a distinction needs to be made between extinction from natural phenomena compared to extinctions brought about by thoughtless human activity?
The plant kingdom is very important because it supports all other forms of life on earth. Without plants, the rest of the living world simply could not survive. This is why it is critical to protect natural ecosystems from exploitation and destruction.
Hopefully, this website will better help you understand the important role plants have played in the past, and will continue to play in the future in shaping the world we live in. .