Anna Dewdney, the author and illustrator of the best-selling “Llama Llama” picture book series, a fixture of story time that in guileless rhyme teaches children not to fear, and to be patient with their mama dear, died Saturday at her home in southern Vermont. She was 50.

The cause was brain cancer, said her partner, Reed Duncan.

Children’s literature is filled with time-honored classics, loved by youngsters who grew up and shared the stories with their children and grandchildren. Little ones first read the garden-hopping adventures of Beatrix Potter’s Peter Rabbit in the waning days of the Boer Wars. “The Cat in the Hat” by Dr. Seuss, made its debut when Dwight D. Eisenhower was president.

Then there are the modern classics, the books that did not yet exist when the parents of today’s children were little. These are the volumes that kids and grownups are currently discovering together, wearing out their pages and memorizing their words until they become part of the fabric of childhood and parenthood.

It was widely agreed that “Llama Llama Red Pajama” (2005), Dewdney’s lushly illustrated tale of a baby llama calling out for Mama Llama at bedtime, was among those modern classics. She wrote and illustrated more than a dozen more installments in the “Llama Llama” series, earning a reputation, a Chicago Tribune reviewer remarked, as a “geographer extraordinaire of the emotional terrain of preschoolers and their mothers.”

Dewdney displayed in her writing career a deep reserve of patience, a virtue that she sought to instill in her young readers. The manuscript for “Llama Llama Red Pajama” languished for years, she said, before Viking picked it up around her 40th birthday.

Until that point, Dewdney had illustrated a handful of books by other authors while supporting herself as a waitress, a furniture saleswoman, a bus driver, a mail carrier, a day-care provider and a teacher at a boarding school for dyslexic boys.

“It was a long road,” she once told the Salt Lake Tribune. “Editor after editor told me ‘Don’t write in verse!’ That was always a mystery to me, because so many classic children’s books are written in verse. But there was a tremendous backlash against it in the 1990s.”

The “Llama Llama” series ultimately became a blockbuster success, selling millions of copies, spawning stuffed animals, games and other merchandise, and inspiring a Netflix animated show slated for 2017 with Jennifer Garner voicing Mama Llama.

Dewdney said she populated her books with llamas, rather than a more commonplace animal, because they had entertained her two daughters when they were young and because she liked the sound of the word.

“Whenever we passed a field that had llamas, I didn’t know what llamas ‘said,’ so I said, ‘llama llama,'” she told the Brattleboro Reformer of Vermont, contrasting the noises emitted by llamas with the “moo” of a cow. “That’s how it started. Now I know that llamas don’t ‘say’ anything, actually. Unless they are in my books.”

In the original book, Baby Llama, freshly tucked into bed, calls for Mama Llama and grows increasingly agitated as the mother finishes her kitchen work and takes a phone call before answering. By the time she arrives, Baby Llama’s eyes have grown into fearful saucers, and the cobalt blue of the bedroom walls has taken on a threatening navy cast.

But all is quickly right with the world, when Mama reassures her baby, “Little Llama, don’t you know, Mama Llama loves you so? Mama Llama’s always near, even if she’s not right here.”

In other books, Dewdney tackled childhood ills such as bullying. “Being bullied is no fun! Walk away … and tell someone!'” she wrote in “Llama Lama and the Bully Goat” (2013).

In “Llama Llama Mad at Mama” (2007), an unexciting errand takes on deeper meaning when Mama Llama explains to her child, “Please stop fussing, little llama. No more of this llama drama. I think shopping’s boring, too – but at least I’m here with you.”

It was perhaps passages such as that one that endeared Dewdney’s books to parents, who showed their own patience by reading the “Llama Llama” books over and over again.

“A good children’s book can be read by an adult to a child, and experienced genuinely by both,” Dewdney told the Newark Star-Ledger. “A good children’s book is like a performance. I don’t feel my world really exists until an adult has read it to a child.”

Anna Elizabeth Luhrmann was born in New York City on Dec. 25, 1965, and grew up in Englewood, New Jersey. Her father was a doctor, and her mother was a writer.

“From the first moment it occurred to me that you could do something for a living, that’s what I wanted to do. I love making up stories and I love doing pictures,” she told the Sentinel-Tribune of Bowling Green, Ohio.

Dewdney was a 1987 graduate of Wesleyan University in Middletown, Connecticut. Her illustrations first appeared in the book “The Peppermint Race,” with text by Dian Curtis Regan (1994).

The “Llama Llama” series includes “Llama Llama Misses Mama” (2009), “Llama Llama Holiday Drama” (2010), “Llama Llama Home With Mama” (2011), “Llama Llama Time to Share” (2012), “Llama Llama Gram and Grandpa” and “Llama Llama Sand and Sun” (both 2015).

Dewdney expanded her animal kingdom with volumes such as “Grumpy Gloria” (2006), featuring a bulldog who confronts the jealousy that she feels over her owner’s new doll, and “Nobunny’s Perfect” (2008), about rabbits learning their manners.

“Nelly Gnu and Daddy Too” (2014) features a large African antelope. “Roly Poly Pangolin” (2010) introduced many children (and perhaps some adults) to the burrowing mammal capable of rolling up into a ball in situations of danger.

“It can be stressful to be a little person, and children get anxious,” Dewdney said. “They need help to understand that the world is not such a scary place, and they’re not alone. And that’s what my books are about. … People love you, and they will help you.”

Dewdney’s marriage to Ronald Dewdney ended in divorce. Survivors include her partner of 18 years, Reed Duncan; two daughters from her marriage, Berol Dewdney and Cordelia Dewdney; her parents, George and Winifred Luhrmann; and two sisters.

“Reading with children makes an intimate, human connection that teaches that child what it means to be alive as one of many beings on the planet,” Dewdney wrote in a 2013 commentary for the Wall Street Journal. “When we read a book with children, then children – no matter how stressed, no matter how challenged – are drawn out of themselves to bond with other human beings, and to see and feel the experiences of others. I believe that it is this moment that makes us human. In this sense, reading makes us human.”