It’s the only science fiction novel I can think of that celebrates the process of composting. Things grow and die and rot and new things grow. Death is frequent and capricious and usually unmourned. Death and rebirth are constant. Life—and Wonder—remain.

The Sense of Wonder is an important part of what makes science fiction work, and it is this Sense of Wonder that Hothouse delivers so effectively, and at a sustained level that Aldiss would not surpass until his trilogy of novels Helliconia Spring, Helliconia Summer and Helliconia Winter, almost thirty years later.

The world of Hothouse is our own planet, inconceivable gulfs of time from now. The Earth no longer spins. The moon is frozen in orbit, bound to the Earth by weblike strands. The day-side of the Earth is covered by the many trunks of a single banyan tree, in which many vegetable creatures live, and some insects, and Humankind. People have shrunk to monkey-size. They are few in number, as are the other remaining species from the animal kingdom (we will meet a few species, and we will converse with one mammal, Sodal Ye). But animals are irrelevant: the long afternoon of the Earth, as nightfall approaches, is the time of vegetable life, which occupies the niches that animals and birds occupy today, while also filling new niches—of which the traversers, the mile-long space-spanning vegetable spider-creatures, are, perhaps, the most remarkable.

The teeming life-forms—which, with their Lewis Carroll–like portmanteau names, feel as if they were named by clever children—fill the sun-side of the world. Gren, the nearest thing to a protagonist that Aldiss gives us, one letter away from the omnipresent green, begins as a child, and more animal than human. A smart animal, true, but still an animal—and he ages fast, as an animal might age.

His odyssey is a process of becoming human. He learns that there are things he does not know. Most of his suppositions are wrong, and in his world a mistake will probably kill you. Randomly, intelligently, fortunately, he survives and he learns, encountering a phantasmagoria of strange creatures on the way, including the lotus-eating tummy-bellies, a comic relief turn that gets increasingly dark as the book progresses.

At the heart of the book is Gren’s encounter with the morel, the intelligent fungus who is at the same time both the snake in the Garden of Eden and the fruit of the tree of knowledge of good and evil, a creature of pure intellect in the same way that Gren and the humans are creatures of instinct.

Sodel Ye, the descendant of dolphins that Gren will encounter towards the end, and the morel are both intelligent, both know more about the world than the humans, and both are reliant on other creatures to move around and encounter the world, as parasites or symbiotes.

Looking back, one can see why Hothouse was unique, and why, almost fifty years ago, it won the Hugo and cemented Aldiss’s reputation. Compare Hothouse with its most traditionally English equivalent, John Wyndham’s disaster novel The Day of the Triffids (1951), a “cosy catastrophe” (to use Aldiss-the-critic’s phrase) in which blinded humans are victimized by huge, ambulatory, deadly plants, band together and learn how to keep themselves safe before, we assume, reestablishing humanity’s dominion over the Earth. In the world of Hothouse there is nothing that makes us superior to plants, and the triffids would be unremarkable here, outclassed and outweirded by the doggerel monsters of the hothouse Earth, the crocksocks, bellyelms, killerwillows, wiltmilts and the rest.