Mind Controlling Invasive Alien Plants

Question

A while ago I was reading a short story / novella, possibly part of an anthology. The Premise was: Human space explorers land on an alien world, and discovers a primitive species that is Stone Age in everything except for horticulture. This species was in fact, weirdly advanced, and weirdly obsessed over caring for their crops. Over time, the human explorers become increasingly worried, although nothing has posed any visible threat. At least one of the humans then figures out that the “crops” themselves are not only not native to the world they are on, but are also intelligent, and telepathic; and that they somehow came to this world long ago, and enslaved the evolving sentient natives to care for them.

This revelation creates a panic among the humans, who begin to fight among themselves on how to solve it. Several decide they should send a signal to earth to stay away, and destroy their ship to prevent the plants from ever leaving that world. However, at least one human succumbs to the plants dominance, and flees with the ship home to “warn earth” never realizing that their own primitive “fight or flight” response had been hijacked by the plants, to trick them into carrying seeds home to earth for colonization.

Answer 1

Joe L. has nailed this in a comment. The story is Isaac Asimov’s short story “Each an explorer”.

In that story, a small crew of spacefaring humans find a planet where the local humanoid population seems generally peaceful and primitive, but aggressively defend a certain cereal plant that they grow in large quantities. The spacefarers speculate that the humanoids have a primitive religion where they treat those plants in a sacred way.

Eventually though, they realise that the plant is telepathically enslaving the humanoids to care for the plants. As they leave the planet, they find out in the spaceship that the plants have mind controlled even them. They seem to have gotten a lucky escape from the planet, and try to warn Earth. But as the final twist, it is revealed that they’re carrying the spores of the plant with them to Earth.

Smith laughed. “You know, you’re completely off base. If those plants really had us under control, why would they let us get away to warn the others?”

Chouns paused. “I don’t know.”

Smith’s good humor was restored. He said, “For a minute you had me going, I don’t mind telling you.”

Chouns rubbed his skull violently. Why were they let go? And for that matter, why did he feel this horrible urgency to warn Earth about a matter with which Earthmen would not come into contact for millennia perhaps?

He thought desperately and something came glimmering. He fumbled for it, but it drifted away. For a moment he thought desperately that it was as though the thought had been pushed away: but then that feeling, too, left.

He knew only that the ship had to remain at full thrust, that they had to hurry.