Final answer:
In the given sentence, 'botanists' means 'plant scientists' who study various aspects of plant life, including their ecological roles and medicinal uses.
Step-by-step explanation:
In the sentence from the story "The Expert": "That’s pokeberry, and some botanists warn against eating the fruit," the word botanists refers to plant scientists. Botanists are professionals who study plant biology, which can include fields such as field biology, ethnobotany, and pharmacognosy. They investigate various aspects of plant life including plant species, their roles in ecosystems, and their uses in medicine and culture.