In The Botany of Desire, how does the author describe how plants encourage animals to seek or avoid them, for example, by emitting...

This book seeks to explore the ways that plants have evolved to encourage animals and humans to do their bidding, i.e. to help the plants to develop survival mechanisms such as gene diversity. The author reasons that plants develop desirable characteristics as a way to, for example, encourage animals or plants to eat them, thereby creating a way for the plants' seeds to be dispersed more widely. Plants might also develop characteristics to help protect...

This book seeks to explore the ways that plants have evolved to encourage animals and humans to do their bidding, i.e. to help the plants to develop survival mechanisms such as gene diversity. The author reasons that plants develop desirable characteristics as a way to, for example, encourage animals or plants to eat them, thereby creating a way for the plants' seeds to be dispersed more widely. Plants might also develop characteristics to help protect them from animal or human interference, so that they can be less vulnerable to damage. 

In the book's introductory chapter, Pollan explains these two primary directives plants have, that of being actively cultivated or left alone. 

"A great many of the chemicals plants produce are designed, by natural selection, to compel other creatures to leave them alone: deadly poisons, foul flavors, toxins to confound the minds of predators. But many other of the sub- stances plants make have exactly the opposite effect, drawing other creatures to them by stirring and gratifying their desires.

The same great existential fact of plant life explains why plants make chemicals to both repel and attract other species: immobil- ity. The one big thing plants can’t do is move, or, to be more pre- cise, locomotive."

This idea of gratification of desire is what inspired the book's title and primary theme: that plants make us want them, and in so doing persuade us to engage in behaviors that help them get what they want (i.e. to survive). The first chapter on the apple focuses on sweetness as a desirable characteristic and a source of pleasure for animals and humans. The taste of the apple and its importance to human beings led to its being imported and cultivated in the New World, for the making of cider (a popular drink among settlers who could not always access fresh drinking water), but also for the enjoyment of the fruit as a sweet and healthful food source. 

The idea of a plant's use of poison to repel potential predators, as opposed to being fatal, ensures that the plant is more likely be merely left alone, as opposed to being destroyed or willfully eradicated.