Thursday, March 2, 2023 from 8 - 10 p.m. on KPBS 2 / Watch now with KPBS Passport!
Two groups of plants exhibit such intriguing behavior that a century and a half ago they attracted the attention of Charles Darwin. These same plants, the orchids and the carnivorous plants, still fascinate scientists today. In two one-hour films, PLANTS BEHAVING BADLY reveals a world of deceit and treachery worthy of any fictional thriller. David Attenborough narrates.
EPISODE GUIDE:
Episode 1: "Murder & Mayhem" Encore Thursday, March 2 at 8 p.m. on KPBS 2
When carnivorous plants were first discovered, they caused uproar in the scientific world. The greatest botanist of the 18th century, Carl Linnaeus, pronounced the idea that they ate insects blasphemous, that it went against the way God had ordered the world. More than a century later, another great naturalist, Charles Darwin, would prove him wrong. Darwin worked on many kinds of carnivorous plants and what he discovered both astounded and frightened him. Here were plants that behaved more like animals! Today we are still finding new surprises in the world of carnivorous plants.
The film travels from the swamps of the southern U.S. to remote, isolated mountains rising above the rainforests of South America, and from Borneo to South Africa searching out the latest astounding discoveries.
Carnivorous plants have evolved three ways of trapping insects – sticky, fly-paper traps, snap traps, like the familiar Venus fly trap, which work along the lines of an old-fashioned mousetrap, and pit-fall traps – the pitcher plants, with pitchers filled with liquid and digestive juices to drown and digest prey.
In South America, we explore the summits of isolated mountains called tepuis. These plateaus are lost worlds, barely known, high above the rainforests of Brazil, Guyana and Venezuela. They are the only homes of the sun pitchers. These pitcher plants have a drainage system built into the traps, to prevent them from overflowing in the constant rain.
In North America, the purple pitcher is full of living insects! It no longer produces enzymes but instead depends of several species of mosquito larvae to eat drowned insects and then drop their waste products into the water. It’s these that the pitcher plant absorbs.
In southeast Asia, the flask-shaped pitcher does the same, but hidden in the depths of these pitchers are carnivorous mosquito larvae that devour other mosquito larvae.
But some pitchers in southeast Asia have formed even stranger relationships. One creates a home for ants in its stems and in return the ants keep the pitcher clean and slippery. The ants also help themselves to the pitcher’s prey and can even swim and dive in the toxic fluid to haul out chunks of insects.
The world’s largest pitcher plant – the Rajah pitcher – grows only on the slopes of Mount Kinabalu in Borneo. Recently, scientists have discovered perhaps the strangest relationship of all.
The Rajah produces nectar that attracts tree shrews. The tree shrews balance on the lip of the pitcher to lick off the nectar and while there, urinate and defecate into the pitcher – nutrients that the plant can absorb.
After dark, the summit rat, a species that only occurs on Mount Kinabalu, takes over. Occasionally, accidents happen. Recently, dead and partially digested rats were found in the pitchers – making headlines worldwide.
Episode 2: "Sex & Lies" Encore Thursday, March 2 at 9 p.m. on KPBS 2
From the rainforests of Borneo, Madagascar and Central America to the roadsides of northern Europe, this film captures the extraordinary beauty of orchids, mysterious and romantic blooms. In nature, such beauty always serves a purpose.
For orchids, it’s a way of making sure pollination happens. Orchids need the help of insects to move their pollen from plant to plant and many use nectar as a reward – as do many familiar plants. But there’s a dark side to orchids – a world of trickery and deception.
This program shows how orchids deceive insects into helping them, using underhanded tricks, including the promise of sex. Bee orchids have flowers that look like female bees and exactly mimic the scent produced by female bees. Male bees are completely fooled and try to mate with the flower. In their misguided frenzy, they pick up the orchid’s pollen.
The orchid family is the largest of all plant families. Some 25,000 different kinds grow throughout the world, on every continent except Antarctica. Many grow in remote rainforests, yet there are equally impressive displays along the roadsides of Europe.
But a few places are hotspots for orchids and a paradise for botanists. One such is Mount Kinabalu in Borneo, where nearly 900 species grow. Some kinds here have only ever been found once in the distant past.
Orchid flowers exhibit an extraordinary diversity. They have a peculiarity in their genetic code that allows them to shape their different flower parts independently, creating floral designs beyond imagination.
Yet all of this diversity is aimed at one thing – ensuring that pollination occurs – a fact that struck Charles Darwin so forcefully he devoted a great deal of time to the detailed study of orchids.
Darwin’s most famous book, "On the Origin of Species," shook the scientific world and far beyond. Yet it was his next book, devoted entirely to orchids, that filled in gaps and firmed up his revolutionary ideas. Darwin discovered many intriguing ways in which orchids have enlisted the help of insects.
Orchids produce thousands of seeds, which are so small they are like dust and too small to contain food reserves. They can only germinate with the help of specific fungi in the soil. In the past, this made orchids hard to grow from seed, a problem now solved by high-tech botanical gardens. This means that some of the rarest can be grown and re-introduced to old haunts. These projects are carried out in such secrecy that it’s like something from a spy movie.
The film visits one of the rarest orchids in one of its secret sites, deep in the swamp forests of the Everglades. This is the haunt of the ghost orchid, a mysterious and sought-after plant made even more famous by a popular novel ("The Orchid Thief") and a Hollywood movie ("Adaptation"), illustrating an enduring fascination with these amazing plants.
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Credits: Produced by Terra Mater Factual Studios.
