Classification of Gymnosperms
So which gymnosperms do we actually have today? Just four divisions in total. But crazy sounding divisions, so you need to bear with me. Let’s look at each one of them briefly. This is important. And we do it in very interesting way, so that you don’t forget it at all.
Let’s start – with the ones that are popular – with the Dinosaurs: Cycodophyta. Cycads are the primitive Gymnosperms that have thick trunks, large compound leaves. What I mean by compound leaves? Now compound basically means it’s not simple, it’s not single, it’s a group – a group that contains many smaller little parts that are called leaflets, which are attached to a single central stem.
Now you know this that the dinosaurs are gone, but the Cycads are hanging out today near the tropics. And some of them are really really tiny. This one is called the Zamia pygmae, the smallest gymnosperm. It’s just this much…just this much – 25 cm in height. And then you have the group that decides that they are going to have their male cones and female cones on separate plants – Gnetophyta or gnetopsida. The gnetophytes are currently only consists of shrubs and woody vines from across 3 distinct genera. These are the names. They happen to have – Now this is important – pretty coats – by pretty I mean they look like flowers, and that’s important. Because this flower-like arrangement gives you an evolutionary connect. They considered to be the direct ancestors to the early angiosperms.
The next group is important. It was very close to the heart , I’ll say of the Chinese, in fact they capitalized on this – the Ginkgophyta. And today, the Ginkgo biloba or the ginkgo tree is the only surviving species of Ginkgophyta. Strange but true. You know why? Because they have the Chinese to handle. The Chinese kept them alive for all the Chinese medicines that it was actually used for. And you know what this medicine is supposed to help in? The seeds and the distinctive fan shaped leaves have been used for thousands of years, in the belief that it improves memory and sharpens thinking. You guys have us to help you learn in the most amazing way, you don’t need Ginkgo seeds or leaves. Ok?
And then finally, Coniferopsida or the Conifers – Pine tree, characterized by their smaller male and bigger female cones as well as needle-like leaves are prime examples of this group. So for the period of about 200 million years they dominated the world’s forests and today there are just 630 species left that thrive at Temperate Climate. So they include medium sized trees, may be even tall trees and shrubs and the typical example is Sequoia sempervirens, commonly called ‘Red Douglas or Caliphornia red wood’.
And now I would like to introduce you to the tallest Gymnosperm in the world. This tree can thrive for over 1800 years and grow over 110 m in height.