Author Michael Pollan will appear at Portland’s Newmark Theatre at 7:30 p.m. July 27. Pollan is the author of “The Omnivore’s Dilemma” and “How to Change Your Mind.” He will discuss “This Is Your Mind on Plants,” a book that explores three plant drugs — opium, caffeine and mescaline — and throws the strangeness, and arbitrariness, of our thinking about them into sharp relief. With his signature blend of history, science and memoir, Pollan examines and experiences these plants from several different angles and contexts. Pollan’s consideration of our attraction to psychoactive plants holds up a mirror to human needs and aspirations and our entanglement with the natural world. Tickets ($28) include a paperback copy of “This Is Your Mind on Plants.” Books will be distributed at the event.