Hothouse is a 1962 Science Fiction novel by Brian W. Aldiss, originally written as five novelettes serialized in The Magazine of Fantasy & Science Fiction in 1961 before being collected and edited to become a single novel. In the US, an abridged version was published as The Long Afternoon of Earth; the full version was not published there until 1976.
Hothouse is set in a far future, the Earth has become tidally locked with the Sun, which has swollen to fill half the sky. With the increased light and heat, plants have become Earth's dominant form of life: a single immense banyan fig covers the Earth's day side, and the smaller plants living within, on and around it are engaged in a constant frenzy of growth and decay. Many are now at least partly mobile, carnivorous or both, many evolving primitive nervous systems and, in some cases, even eyes and limbs. The only animals to survive within this jungle are certain species of giant eusocial insects and small groups of humans, reduced to a fifth of the size they are now.
In this jungle world, a human tribe undergoes a pilgrimage to the treetops to send its elders Up, securing them in transparent seedpods that will be picked up by immense spider-like plants and carried off to what the humans believe the be their afterlife — but which is in reality the Moon, rendered habitable by millions of years of plants colonizing it, and along the journey solar radiation will scar and mutate them into strange new forms. The young, as they head back to the middle levels, try to hunt a giant vegetable-bird but are picked up and carried off to the distant coasts. There, Gren, one of the tribe's few boys, becomes attached to a symbiotic, sapient morel, and after a power struggle is forced to leave the tribe alongside his partner Poyly. The two exiles set off through the jungle to follow their tribe, but the morel's plans and a chance encounter with a tribe of plant-animal herders will set Gren off on a long journey around the world and through strange realms, leaving the familiar world-jungle for tribes of men connected to trees by umbilical cords, islands of living rock, and the cold, twilit world of the planetary terminator.
This work provides examples of the following tropes:
- Amazing Technicolor Population: The future humans have green skin.
- Big Creepy-Crawlies: The surviving insects of the far future — tree-bees, plantants, tigerflies and termights — have grown much larger and more fearsome than their forebears, matching the shrinking future humans until they both reached roughly the same sizes.
- Bilingual Bonus: May be unintentional, but Gren's name means "branch" in Swedish, suitably for someone who's lived almost his entire life in a gigantic tree.
- Butt-Monkey: The tummy-belly men, who spend the majority of their time in the story being subject to all kinds of physical and verbal abuse from Gren, the morel and the narration, humiliating themselves in various ways, dying off in undignified manners and ultimately being left behind to die when Gren decides he's tired of them.
- Cobweb of Disuse: Metaphorically. The narration notes that, fittingly, the Earth's old age is marked by its upper reaches becoming draped in the immense webs of spider-like plants.
- Combat Tentacles: A large number of plants have adapted their tendrils and roots into workable tentacle equivalents, and use them to great effect in hunting each other and the few remaining animals. Particularly notable is the killerwillow, a coastal plant that lives and moves entirely underground and uses its root system like the tentacles of a monstrous octopus.
- Death World: The jungle that covers the day side of the far future Earth is an immensely deadly place to live. Resources are few, almost every plant is toxic or carnivorous, and deadly predators — including giant insects and the aforementioned plants — lurk in every thicket, every branch, every pocket of wood. Every outing carries a real risk of death, and people are very used to seeing their tribe members die in front of them. The rest of the world is no kinder — the ocean is filled with viciously carnivorous seaweed, and the plants of the sea and the shore are in a constant state of genocidal combat with one another.
- Epigraph: The story begins by quoting two lines from Andrew Marvell, a 17th century poet.My vegetable love should grow
Vaster than empires and more slow — "To His Coy Mistress" - Future Primitive: The future humans have greatly regressed from their civilized past, becoming small, fearful creatures living sustenance lives in the dayside rainforest.
- Genetic Memory: The brains of the future humans contain records of the entire human species' history, stretching back to the present day and far into prehistory. These is normally buried too deep for them to recollect, although the symbiotic brain-fungus can access them if it bonds with a human. This ends up putting the fungus in the position of being the first creatures in a billion years to live in more than just the moment, granting it recollection of the past and a sense of perspective and time that no other creature in the world-jungle has.
- Giant Spider: They're not actual spiders, but traversers are plants roughly analogous to spiders in shape and capable of spinning a form of vegetable fiber. They're also each a mile in length when in the atmosphere and much larger in pressure-less space, and their webs are strong and extensive enough to connect the Earth and Moon.
- Human Subspecies: Numerous offshoots of humanity exist in the distant future, at varying levels of intelligence and adaptation to their often hostile environments.
- The main kind seen are a diminutive, green-skinned people who live in the depths of the world-forest's canopy.
- The Fishers, also referred to as tummy-belly men, live symbiotically with large stout trees to whom they're connected by long umbilical cords. They depend on their trees for almost everything, and possess very limited intelligence.
- The Arablers were a people with limited agricultural skills who settled the edges of the world's night side. They were largely displaced by further waves of migrants, and by the story's time have become entirely non-sapient beings kept as carriers, servants and beasts of burden by a species of sapient dolphins.
- Innocent Fanservice Girl: None of the future humans wear clothes. Lily-yo assesses her bare breasts in one scene, disappointed that they're much saggier than they used to be.
- Insufferable Genius: The morel and the Sodal Ye are genuinely and by a good margin the most intelligent, imaginative and well-informed characters in the story. They are also intensely arrogant and condescending, and make little secret of their contempt for other beings.
- Just Before the End: The narration makes it clear that, in terms of stellar lifetimes, the Sun is not far from going nova and wiping out the solar system. At the end of the novel, the end begins in earnest, as Earth's vegetative life begins beaming itself into space in preparation for the world's impending demise.
- Man-Eating Plant: Many of the future Earth's plants are actively carnivorous. As many plants have long since evolved equivalents to nervous and muscular systems of animals, these are more often than not entirely capable of ensnaring and devouring humans, the other surviving animals, and each other. In many cases, they're entirely mobile beings that can actively stalk and subdue their prey. In the ocean, the algae are no less mobile or hungry. Many do not feed on flesh or other plants directly, instead using their prey's rotting tissues fertilize their roots, but others are carnivorous in the more direct sense.
- Nothing Is Scarier: It's never explained what actually lives inside the Black Mouth, or how it is that it draws other creatures to itself — all that's shown is that something lives inside the volcano, the power its voice has over all living things, five long chitinous fingers emerging from the volcano's crater and being withdrawn, and the character's feeling that something awful waits within.
- Nuclear Mutant: Traveling from the Earth to the Moon exposes you to radiation, causing humans to mutate and begin transforming into flymen.
- Our Humans Are Different:
- The far-future humans are short — about a fifth as much as a modern human — and green-skinned, live very close to the bottom of the world-jungle's food chain, and rely much more on instinct than on their own stunted cognition.
- As is revealed through the morel's plumbing of human Genetic Memory, modern-day humans were actually ape-fungus symbiotes, having bonded with a form of sapient fungi in the Oligocene to bond the animal's strength and senses with the fungus' cognition. The fungi eventually adapted to live entirely within the proto-humans' skulls, merging with their brains to become a single compound being, and allowed humanity to rise to full sapience. This lasted until the Sun began to swell and brighten in its old age, at which point the excess radiation killed off the symbiotic fungi and cause humanity to revert to a savage, primitive state.
- Patchwork Story: The novel is a "fix-up" of five novelettes, originally serialised in The Magazine of Science Fiction in 1961. These stories were "Hothouse", "Nomansland", "Undergrowth", "Timberline" and "Evergreen", published between February and December 1961.
- Planimal: The far-future plants have in many cases developed mobility, nervous systems, eyes, limbs and other such organs and structures. They have long since outcompeted the majority of the animals, and the bulk of the world-jungle's fauna consists of a variety of plants evolved into the niches formerly held by animal life.
- Sapient Cetaceans: The Sodal Ye, a sapient dolphin descendant. It has a good claim to being the most intelligent creature in a world where most sapient beings range from stolidly unimaginative to simply idiotic; as a consequence, it's also incredibly conceited and condescending.
- Siren Song: The unknown creature that lives within the Black Mouth, which sings a terrible, entrancing song that causes anything that hears it irresistibly run towards the volcano it lives in and hurl itself in.
- Spike Shooter: Certain species of cactus in the coastal nomansland have developed the ability to launch volleys of their spikes.
- The Symbiote:
- The morel, a fungus which has survived into the future by evolving the ability to attach itself to other creatures to serve as a secondary brain, greatly increasing their intelligence in exchange for food and protection. It's quite common in the Nomansland, where almost every sort of creature — from giant termites to predatory trees — can be seen bonded to a morel. Beyond that, as the morel discovers by exploring a human host's Genetic Memory, modern-day humans lived in symbiosis with a similar fungus as well, one adapted to live within their brains, and the downfall of human civilization came about when increased solar radiation killed off their fungal symbiotes and robbed them of most of their intellect.
- On the Earth's dark side, some surviving animals have come to depend on each to survive. A species of bat, for instance, has taken to ferrying spider eggs to high mountains that get just enough sunlight to warm the eggs into hatching, and then carries the spiderlings back; in return, the spiders weave a secondary net that they dip into bodies of water, catching fish for the bats to eat.
- Terraform: The Moon was terraformed, largely by accident, by the traversers. These originally wove their webs towards the Moon to have somewhere to anchor lines with which to bask in solar radiation and away from their predators on Earth, and their migrations gradually carried over seeds and wisps of gas that slowly seeded the Moon with air and plant life.
- Tidally Locked Planet: Two interlocking cases, as the Earth and Moon' pull on each other gradually negated the motion of their respective rotations.
- The Earth is locked to the Sun, and is divided between a constant dayside covered in riotous plant growth and a dark, frozen Nightside.Above them, paralyzing half the heavens, burned a great sun. It burnt without cease, always fixed and still at one point in the sky, and so would burn until that day — now no longer impossibly distant — when it burnt itself out.
- The Moon's tidal locking has itself progressed further over millions of years, so that its orbit now perfectly keeps pace with Earth's day/night cycle. As a result, the Moon floats over one sole area of Earth's surface, making travel to it possible by "traversers", enormous spider-like plants capable of passing through space on silk strands miles long connecting the Earth to the Moon.
- The Earth is locked to the Sun, and is divided between a constant dayside covered in riotous plant growth and a dark, frozen Nightside.
- Treetop World: In the distant future, after the Earth has become tidally locked with the Sun, millions of years of intense humidity and heat have allowed plant life to completely dominate the world. The greatest of all these plants is a single, titanic banyan fig that covers the entire dayside surface of the Earth, forming an immense three-dimensional jungle. Scattered human tribes live at various levels within the volume of the canopy, avoiding the dangers of the dark, rot-shrouded Floor and the sunlit Tips where the most active predators flourish, alongside hardy eusocial insects and an endless variety of carnivorous plants.
- Troubling Unchildlike Behavior: Every kid is forced to become a warrior, learn to kill, and have more children quickly, because the death rate is so high in this future.
- Wacky Wayside Tribe: The characters meet multiple unusual peoples and beings over their journey, such as the Herders, the Fishers, the siren in the Black Mouth and the sharp-furs, most of which serve little purpose beyond spicing up the diversity of Earth's future life and providing dangers along the story's route.
- Was Once a Man: The flymen are former humans, who have been mutated by exposure to intense radiation between the Earth and the moon.
- Weird Moon: The Moon has drifted far enough that it's no longer in Earth's orbit, and instead travels on a parallel orbit with it around the Sun. The two exert just enough gravity on each other to keep them both moving at the same speed, allowing for travel from one to the other.
- Wicked Wasps: Tigerflies, wasp descendants grown to be as large as the surviving humans, are among the few surviving insects in the far future and are dangerous predators and parasitoids. The narrative frequently describes them as wicked and frightful, and they are among the humans' most dangerous foes.
- World Tree: The great banyan that covers the dayside continent is the single largest and oldest entity alive in the world. As Earth's temperatures grew in the past and trees spread and competed more and more fiercely with one another, the banyans' tropical origins and ability to spread indefinitely horizontally allowed them to flourish and displace other plants, until they eventually fused with one another to become a single mammoth plant that dominated all forests before becoming all forests. It now forms the home and world of almost all surviving creatures, covering every part of the continent in layer upon layer of growth and stopping only at the sea and at the day/night terminator.
