top of page
STEP 1: IDENTIFY
Perhaps you imagined a plant that ...
Interestingly, the story of plant evolution actually began in the water!
​
Modern land plants share a common evolutionary ancestor with green algae
(aquatic organisms able to carry out photosynthesis).
This ancestor is thought to have also been a species of green algae.
​
Plants began to populate land at least 475 million years ago and have since diversified into approximately 290,000 living species!
​
Not all plants exchanged water for land however... you may have heard of the waterlily or the lotus?
The plant kingdom is incredibly diverse! An easy first step for classifying plants is to categorise them into:
LAND PLANTS
AQUATIC PLANTS
Think of a plant...
single celled green algae
Let's focus on Land Plants...
Land Plants can be broadly categorised into...
-
Bryophytes
-
Pteridophytes (ferns and lycophytes)
-
Gymnosperms
-
Angiosperms
Pteridophytes
Ferns, lycophytes ('fern allies'), horsetails
-
Vascular plants that reproduce via spores
-
Do not produce flowers or seeds
Sori
Sori are the small spore producing structures found on the underside of fern leaves specifically
%20Branch%20I.jpg)
Lycophyte
Bryophytes
Liverworts, hornworts, mosses
-
Found in moist/damp environments
-
Small, NON-vascular
-
Do not produce flowers or seeds
Mosses against Climate Change...
Peat bogs are mainly comprised of a moss called Sphagnum.
Sphagnum Peatlands absorb and store HUGE amounts of carbon dioxide - one of the well known greenhouse gases.
In fact, peatlands are the largest natural carbon store on land! Who knew that mossy bogs are helping to combat global warming!
Interesting Fact!
Bryophytes were the only plants on earth for 100 million years!
Moss
Angiosperms
Diversity of Flowering Plants
-
Vascular, flowering plants which produce seeds
Interesting Fact!
In the Early Cretaceous period, around 90-130 million years ago, the angiosperms underwent major diversification. This initiated important changes in the ecosystems on land and generated most of the plant diversity that exists today...
Another key characteristic of angiosperms is that they form fruit. After all, fruit forms from the ovary of the flower!
Gymnosperms
Conifers, Cycads, Gingko
-
Vascular plants which do not produce flowers, but do produce cones and seeds
Interesting Fact!
Gymnosperms were the dominant plants during the age of the dinosaurs (Mesozoic era)
Gingko survived the atomic bomb!
Six trees of Gingko biloba (picture above) still grow about 1 mile away from the centre of Hiroshima, where the atomic bomb of 1945 caused devastation.
Few other plants survived this catastrophe, but the ginkgo trees managed to survive and can still be found there today.
Cycad
Pine cone of a conifer tree
Vocabulary Check:
-
Vascular tissue = the transport system (xylem and phloem) in plants which allows for movement of water and mineral nutrients around the plant​​​​​.
​​
-
Non-vascular plants, such as moss, do not need the xylem and phloem structures. Partly due to their small size, they are able to transport water and mineral nutrients via diffusion.
​​
-
Vascular plants are more complex in structure and larger in size, and therefore a more complex system of vascular structures are required.
bottom of page