"A few of my favorite things" have an actual name

"A little-known piece of trivia," Altman announced."This smell, after it rains for the first time. You know what's that called?"
"Is this going to freak me out?"Williams said.
"Petrichor," Altman said. "It's my favorite smell. You only get to smell this once or twice a year, because it has not to rain for a while, and then rain. It's the smell of summer in St. Louis."
"Petrichor?" Williams said, uncertainly.
"Petrichor," Altman said.