The weeping and speaking trees in Virgil and Dante suggest that the idea of communication with plants is of great antiquity, but only in the sense of the transmigration of human souls into plants; the subject is not yet actual plant intelligence in its own right.
Then comes the transition example in the first part of William Hope Hodgson’s book. The Glen Carrig Ships (1907). In the chapter ‘The Land of Loneliness’ we are taken to an island where there is a cry during the night, and the evil trees are prone to envelop the unsuspecting traveler with their branches. The narrative suggests that human souls are somehow absorbed into the trees and then invite more to join them. The sense of horror is peculiar and powerful. The atmosphere is that of supernatural fear, but the work can count marginally as science fiction.
Then comes the great age of science fiction magazines, and all sorts of depictions of intelligent plants flourish in literature.
Dating back to the early years of pulp science fiction, Murray Leinster’s ‘Proxima Centauri’ shows malevolent space-faring plants attacking human explorers. A more subtle approach comes from the plant intelligence of the entire planet in Clark Ashton Smith’s 1931 story ‘Seedling of Mars’, where humanity is subjugated by the promise of utopia. Raymond Z Gallun, another classic 1930s writer, produced a more evocative variation on this theme in ‘Seeds of the Dusk’, where this time humanity is gassed to peaceful death by an alien plant invader in the distant future. In this last story, the reader is made to feel that the elimination of the last degenerate humans is not a great loss for the world.
As a change from these threats, in Clifford D Simak’s all meat is grass (1965) we actually encounter benevolent (if somewhat ruthless) intelligent life in plant form, although the form it takes is that of a planetary biological computer that works through photosynthesis, and is only outwardly life-like. vegetable we know. all meat is grass is one of Simak’s best novels, a pleasure to read. Proclaiming the brotherhood of all species in its kind, humane and inimitable style, however, there is nothing soft or flabby about it, and it packs a lot of excitement, menace and that impact of a strange cosmos on ordinary life, which is the hallmark. distinctive of a certain subgenre of science fiction, what could be called the cataclysm of small towns.
What happens to the plant civilization considered in itself, without taking into account its impact on humanity? For this you have to go to Olaf Stapledon, at 8 pages in star maker (1937) in which he recounts the rise and fall of the ‘plant men’ of a small, hot, energy-rich world. The history of the beings he describes is dominated by the tension between their nocturnal active nature and their diurnal contemplative nature. The balance is finally lost, and first one, then the other nature predominates, leading to the doom of the plant-men and their world. In 40 years of reading science fiction I have never come across anything remotely comparable in intensity to these 8 pages, when it comes to the subject of plant intelligence. It is a parable of universal relevance to all cultures, in its emphasis on the vital importance of fidelity to one’s natural origins.
