After you’ve had a memoir on the best-seller list for almost 200 weeks and have been played in the movie version by Julia Roberts, people can get a little mean. Seven years after the publication of her blockbuster, “Eat, Pray, Love” (and its less successful follow-up, “Committed”), Elizabeth Gilbert’s novel “The Signature of All Things” enters the water with sharks circling.

Surprise, hammerheads. No matter where you stand on “EPL” (my take was EAT: good, PRAY: so-so, LOVE: oy vey), there is no doubt that “The Signature of All Things” is a captivating novel, the kind in which intellect, imagination and language conspire to create a blissful diversion. I read all 499 pages in a day, then hunted down a copy of Gilbert’s delightful first novel, “Stern Men,” a Dickensian comedy set on lobstering islands off the coast of Maine.

Gilbert’s latest is a big, ambitious novel spanning the life of a woman botanist born in 1800. Alma Whittaker is the daughter of a thieving British urchin who traveled with Captain Cook and became “one of the three richest men in the Western Hemisphere.” Her mother is a tough-minded, well-born Dutchwoman. Alma grows up on a lavish estate on the banks of the Schuylkill River in Philadelphia. With her wiry red hair and blocky nose, Alma is no beauty, but she “could take apart an argument the way a good soldier can dismantle his rifle – half asleep in the dark, and the thing still comes to pieces beautifully. Calculus put her into fits of ecstasies. … She also loved her microscope, which felt like a magical extension of her own right eye, enabling her to peer straight down the throat of the Creator Himself.”

One of the first major complications in Alma’s young life is her parents’ adoption of an exquisitely lovely, perfectly behaved sister whose parents, servants on the estate, have died in a grisly murder-suicide. If there ever was a smart one and pretty one, the Whittaker sisters are it. Things do not go smoothly between them, but ease up a little when the sisters are befriended by a wonderfully kooky friend, Retta Snow. The development of the characters of Prudence and Retta add rich subplots to the book, involving the abolitionist movement in Philadelphia, the 19th century understanding of mental illness and a kind of Midsummer Night’s Dream of mismatches and frustrations in love.

Alma is a polymath, but her true love is botany, and she finds her calling when she begins to study the seemingly lowliest of all specimens, moss. Seen through her magnifying glass, the epiphytes present a “tight little timberland,” “a stupefying kingdom,” “the Amazon jungle as seen from the back of a harpy eagle … rich, abundant valleys filled with tiny trees of braided mermaid hair and minuscule tangled vines … warm estuaries, miniature cathedrals, and limestone caves the size of her thumb.” Her studies of moss, undertaken over three decades, eventually lead her to a new understanding of time – her model involves Divine Time, Geologic Time and Human Time – and, in turn, to a fairly clear vision of what we now call, thanks to Charles Darwin, evolution.

Though Alma discovers sexuality at a young age through a collection of old pornographic books and in the solitude of a hidden closet off the library, her first crush never returns her interest. She is no longer a young woman when she finally meets a man, a dreamy artist quite a bit younger than she is. Ambrose Pike, a lithographer who specializes in beautiful drawings of orchids, holds spiritualist beliefs about the magical and the divine – and seems to be as enchanted by Alma as she is by him. Their relationship eventually takes the story to Tahiti, where a new set of characters and adventures awaits, and the final act plays in Amsterdam late in the century.

In a recent interview, Gilbert described “Eat, Pray, Love” as “my great enabler, my great patron,” giving her the freedom to “pursue my own private literary passions in whatever direction I wanted.” Well, hooray for old “Eat Pray Love,” then. “The Signature of All Things” shows what fiction can do at its finest, blowing other literary genres out of the water.