Excerpt 3 Plant Evolution Plant Algae to Angiosperms from the book Scienceforthe Gardener to be published 2017
Before I continue, let me take you on a short journey back to the future.
Many of the very earliest plants have become extinct, along with the dinosaurs, and can only be recognised from fossil remains. A fossil, as I am sure you know is the impression, of an actual plant or animal that was alive in prehistoric times. It takes the form of stone, just like the Stramatolites, which were originally bacteria.
But let me tell you about some living fossils. Three trees that were thought to be long dead have been found alive and well. Three trees that we know from fossils lived alongside dinosaurs and have only recently been rediscovered
The three trees illustrated, the Gingko, the Wollemi Pine and the Metasequoia, all recognisable from fossil records, were all thought to be extinct.
The Gingko Biloba was discovered last century in China. Interestingly it is the only species of this genus growing to over 100 feet tall. A welcome find as Gingko leaves are now being used in herbal remedies for complaints such as vertigo and dementia and generally into Alzheimer’s Disease.
The next tree, the large Dawn Redwood, a member of the Taxodiaceae family, and thought to have been extinct for 5 million years, was discovered in 1946 in Szechuan China.
It is a vigorous growing deciduous tree with very attractive soft and feathery pinnate leaves and similarly to the Gingko can reach a height of over 100 feet. It is also known as the Swamp Cypress. It is tolerant of water-logged soils where many existed in prehistoric times.
Most exciting, and discovered very recently, is the new living fossil called the Wollemi Pine. It was found in Eastern Australia in 1994 and has been classified in the Araucariaceae family along with another very ancient prehistoric tree the Araucaria – the Monkey Puzzle tree. Strictly these are known as the Puzzle trees. The name Monkey is rather incorrect!
The Wollemi Pine is one of the oldest and rarest plants believed to date from the time of the dinosaurs.
At the time of writing this book there were less than 100 adult trees known to exist in the wild and extensive research is being undertaken to safeguard the survival of this very important genus. Fittingly this very special living fossil tree is named Wollemi Noblis after the wild life officer David Noble who came across the tree in a canyon in an inaccessible part of Wollemi Park not far from the Blue Mountains in Eastern Australia.
I have been lucky enough to see two Wollemi saplings, one in a small public garden in Akaroa, New Zealand and one in Bristol Botanic Gardens uk so hopefully these one-time fossils will live on for generations to come. If you would like to try to grow one yourself they are available to purchase online from specialist distributors.
And now back again to prehistoric times in the next excerpt Algae!!