C4 Photosynthesis

Supercharged plants
32-25 million years ago

Plants have been busily harnessing sunlight to make sugar for hundreds of millions of years – a process called photosynthesis. But fairly recently, some plants have found a better way to do it. C4 photosynthesis is far more efficient than normal photosynthesis, allowing C4 plants to cope with harsh conditions. Today scientists are trying to engineer rice to use C4 photosynthesis, to help feed the growing population.

See other: History of Life

Flowers Flower

Plant revolution
130 million years ago

This may sound strange, but flowers are a quite recent invention. There have been land plants for 465 million years, yet there were no flowers for over two-thirds of that time. Flowering plants only appeared in the middle of the dinosaur era. The equally-familiar grasses appeared even more recently. The oldest fossil grasses are just 70 million years old, although grass may have evolved a bit earlier than that.

See other: History of Life

Brier [Noun.]

Any of many plants with thorny stems growing in dense clusters, such as many in the Rosa, Rubus, and Smilax genera. (Alternative spelling of briar.)

‘From “desire”: desirable–admirable from “admire”,
Lumber, plumber, bier, but brier,’
– Gerard Nolst Trenité, The Chaos

Plants Colonise the Land

Out of the sea
465 million years ago

Some animals ventured onto land as far back as 500 million years ago, but they only visited briefly – perhaps to lay eggs in a place without predators. Plants were the first to take up permanent residence on land. The first land plants were relatives of green algae, but they rapidly diversified.

See other: History of Life

Second Half of the Paleozoic Era

The Phanerozoic eon, in which we currently find ourselves, is divided up into three eras: the Paleozoic, Mesozoic and the Cenozoic. The Paleozoic era, which spans 541 to 252.17 million years ago, contains the following periods: Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian. Let’s consider the last three divisions of the Paleozoic era:

Devonian period (419.2–358.9 million years ago)

Even though the Devonian period is called the Age of Fish, it is perhaps more famously marked by our vertebrate ancestors taking to the land. The first vertebrates lived as amphibians; their skeleton – as opposed to exoskeleton animals – is on the inside of their body allowing their skin to be more porous.

Pectoral and pelvic fins of these amphibious tetrapod vertebrates have been observed to gradually change into harder extremities – legs. Some of the oldest fossilised footsteps have been discovered in Poland, dated 397 million years ago. All present-day tetrapods (everything from humans and frogs to crows and geckos) to can trace their ancestry to these Devonian pioneers.

Also, some plants developed a woody covering for back support which allowed them to grow taller than other families of plants in their search for sunlight. The first forests appeared in the Devonian period.

Carboniferous Period (358.9–298.9 million years ago)

The Carboniferous period intensified the forestation of Earth even more. Meanwhile, amphibious lifeforms started to diversify; in order to escape the competition, some gradually developed more tough skin to venture out of the water for longer periods of time. Over time, these animals also managed to lay eggs with a more hardened shell which allowed them to nest on land – these land-lovers would become the ancestors of reptiles.

Permian Period (298.9–252.17 million years ago)

During the Permian, all the continents of the world finally coalesced into one supercontinent, named Pangaea (meaning ‘the entire Earth’). As the globe warmed up and the ice retreated, many areas of Pangaea became very arid; many of the Earth’s forests therefore dried out. Reptiles, however, thrived in this transformed environment.

The Permian ended with the most extensive extinction event recorded in paleontology: the Permian-Triassic extinction event, also know as the Great Dying. 90% to 95% of marine species became extinct, as well as 70% of all land organisms. It is also the only known mass extinction of insects. Its cause is still debated but the most dominant theory is an environmental disaster caused by volcanoes in Siberia.

Ross: I’ll be at the bottom of the dating barrel. The only guys below me will be four-divorce-guy, murderer-guy, and… and geologists.
– Friends (1999) Season 6, Episode 2; “The One Where Ross Hugs Rachel” [No. 123]

See other: History of the Earth

Gympie Gympie

The Gympie-Gympie (pronounced gimpey-gimpey) is one of four species of stinging tree of the family Urticaceae in Queensland, Australia. It is said to have the most painful sting of any plant, not only in Australia, but the World.

“I like it when a flower or a little tuft of grass grows through a crack in the concrete. It’s so fuckin’ heroic.” – George Carlin

Although called a tree, the Gympie-Gympie is a soft-wooded shrub that can reach 4-5m, but is often found as a smaller shrub around 0.1-1m tall. It has broad, oval or heart-shaped leaves (which appear furry due to a dense covering of tiny stinging hairs) with saw-tooth edges, and white or purple-red fruit. The stems and fruit are also covered in the stinging hairs.

When touched, the tip of the hairs break off which turn the hairs into a self-injecting hypodermic needles. It is reported that brushing against it is like being burnt with hot acid and electrocuted at the same time.

The actual chemicals contained in the toxin are not completely understood; however, it is probably a peptide (organic chemical molecules made from linking amino acids together in a certain order) called moroidin, hence the plant’s taxonomic name Dendrocnide moroides.

After a person has been stung, the small hairs can become embedded in the skin, which can lead to long-term pain and sensitivity – there are many accounts of people suffering heavily for months from a sting.

Worse still, the Gympie-Gympie is just as capable of stinging when its leaves are dead. The toxin in the hairs seems unaffected by age.

One account a soldier in the bush during World War II was caught short of toilet paper, used the wrong leaf, and was in so much pain that he shot himself in an attempt ease the pain. In 1866 a surveyor reported that his pack horse was stung by the plant, went mad and died in two hours.

“…and then, I have nature and art and poetry, and if that is not enough, what is enough?” – Vincent van Gogh

Lignify [Verb.]

To become wood; that is to say, in botany, to develop woody tissue as a result of incrustation of lignin (a complex non-carbohydrate aromatic polymer present in all wood) during secondary growth (which results from the cell division that causes stems and roots to thicken).