Author Sarah Vowell, who, like many nationally known writers, lives in a New York City apartment, is freaked out by the wild ruthlessness of ban­yan trees.

"I know, I’m fixated on ban­yan trees, the creepiest trees on earth. Tree monsters! People in Hawaii are used to them, but they kill everything in their path. I identified with them because they remind me of how I think. There’s a kind of core structure, but they keep branching out in all directions, dripping down, supporting more and more rickety outer branches. They don’t grow in a straight line, and nor do my books," she said by phone from New York.

Vowell’s latest is called "Unfamiliar Fishes," a meditation on the bookend whammies of the Hawaiian kingdom, starting with missionaries and ending with annexation. And ban­yans figure prominently.

Vowell’s quirky histories have become part of the national dialogue, and she has also become one of National Public Radio’s prize discoveries, delivering essays on the American scene with her chirpy, regular-person voice. Her last best-seller was "The Wordy Shipmates," about the Massachusetts Bay Colony, beginning a fixation on early American religious ethos. (Young fans might know her as the voice of teenager Violet in Pixar’s "The Incredibles.")

Like many others, Vowell first came to Hawaii not to see the islands, but to gaze upon the shattered, seeping hulk of the USS Arizona in Pearl Harbor.

"I wasn’t really thinking about it at the time, in 2003, but being a New Yorker, there were so many comparisons to the attack here in 2001 and Pearl Harbor, and maybe in the back of my mind, I just wanted to see that," she said. "I came to see the site of a terrible attack. That’s how I prefer to spend my free time. And since I like historic sites, I visited ‘Iolani Palace.

"Most people have these visions of Hawaii as a kind of dream vacation, not an actual place — sitting on a beach, drinking an umbrella drink, and that is not my idea of fun."

Hanging with a group of California friends in Hono­lulu to see a concert, another Vowell visit unlocked the islands for her.

"I found myself trying to talk the Californians into going to see the palace and how interesting it is, what a fascinating story. But none of them wanted to leave the beach. They just wanted to lollygag in the sun, as haole tourists do. I got worked up trying to interest them — and I guess that was the moment I clued in on my own passion and the need to tell this story."

Vowell’s path bypasses the usual big events in American history. "I’m more about the eccentric corners, the less well known. … I don’t write about the Revolutionary War and World War II, the Kennedy assassination, things people are already pretty aware of. (I prefer) things that, to me, are fascinating and underexplored in the culture at large."

AND SO SHE dived in, researching Hawaii’s early history by going back to original sources. She probably read everything in the archives at the Hawaii Mission Children’s Society, and describes her job as primarily sitting, reading and occasionally giggling at musty anecdotes. Unlike most creakingly dry history books, Vowell doesn’t lecture the reader. She’s not comfortable in that role.

"I’m unable to offer you that serv­ice. The upside is that I can be inclusive in my stories, and the reader can learn along with me. A lot of the time, what I’m writing about is not just what I’m learning, but how I’m learning it. Like, I was staying in the Ilikai and walking to the Mission Houses, and there I was, in Hawaii’s first condo, studying in Hawaii’s first frame house.

"I was born in 1969, and ‘Hawaii Five-0’ was on, literally, every day of my childhood, and staying in the building that Jack Lord stands on, the same building I saw every day as a kid, and then learning about Chinn Ho, the developer of the building, and then how Chin Ho Kelly was named after him, and how all that fit together — love it! It’s like knitting or something."

She had to get used to the Hawaii way of doing things — not good or bad, just different to an East Coast scholar.

"Hawaii is just so particular. Coming from New York, certain things seem so different. Reverence for families and ancestors. Don’t get me wrong, we love our families, but ancestors? Most Americans don’t keep track of that.

"I know that the Hawaiian ‘melting pot’ comes from some nefarious impulses, the decimation of Hawaiians by disease and the deliberate importation of all these different cultures and people so they can’t communicate with each other and rise up against their bosses. I know all that, and yet it’s kind of my ideal place. I’m not a purist. I love it when things get mixed up and jumbled and thrown together. I like that!"

Which explain why Vowell’s central metaphor in "Unfamiliar Fishes" is the plate lunch, with different ethnic foods all kapa­kahi.

"It’s wonderful to me that people take their history personally (in Hawaii). Sure, there are people who still hold a grudge against the United States and are less than thrilled about being American citizens, and — as someone who travels studying American history — that’s not true in the continental U.S.

"I basically write books for people who do not care about history, and those people are called Americans. So it was a bit of adjustment being in Hawaii where everyone seems well schooled in their local history, and still ticked off about it! Everyone was so engaged with the past and knowledgeable and willing to converse about it. You couldn’t open the newspaper and read the letters to the editor without someone making a begrudging allusion to 19th-century history."

Vowell said she questions everything and anything, particularly when she starts to believe in it herself.

"Studying history for a living, I’ve really learned to fear the people who are certain they are right. So, let’s get in a condemnation of Hitler, that’s always a crowd-pleaser.

"No one thinks they’re a villain. I’m fascinated with finding out why people do what they do. History’s biggest villains? They’re the ones with the biggest ideals. All of your successful mass murderers had some concept behind what they were doing. A psychopath can kill a few people, but to kill millions of people? That’s dreaming big.

"I don’t think I could have written this book when I was younger, because now I have more empathy with people I disagree with. Because at this point I’m so aware of my own failings that I’ve become more open-hearted about others’ failings. These people are not historical cutouts to me. They’re real people.

"And I know, I just know, that I’ve made some choices that, a hundred years from now, aren’t going to look so good."