Johns, a versatile film and stage veteran who won a Tony Award in 1973 for her role in the Stephen Sondheim musical A Little Night Music and was nominated for an Oscar for the 1960 film The Sundowners, died of natural causes at an assisted living facility in the Los Angeles area, said her manager, Mitch Clem.
She appeared in dozens of films in a movie career that spanned more than 60 years but her role in Mary Poppins as Winifred Banks, the distracted suffragette mother who seems to care more about her cause than her two children, was the one for which she will be most remembered.
The movie was nominated for 13 Oscars and won five. Julie Andrews, as the nanny who flies with the help of an umbrella and brings together the family, won as best actress.
Johns also played a flirtatious mermaid in Miranda (1948), and then appeared in dual roles in the 1954 mermaid sequel, Mad About Men (1954). She said she had no problem with the mermaid outfit.
"I was quite an athlete, my muscles were strong from dancing, so the tail was just fine. I swam like a porpoise," Johns told Newsday in 1998.
She was nominated for an Academy Award as best supporting actress for her role as a hotel keeper in the Australian-set adventure The Sundowners alongside Robert Mitchum, Deborah Kerr and Peter Ustinov.
"As far as I'm concerned, I'm not interested in playing the role on only one level," she told The Associated Press in 1990.
"The whole point of first-class acting is to make a reality of it. To be real. And I have to make sense of it in my own mind in order to be real."
Johns was an accomplished stage actress as well. Sondheim penned the bittersweet song Send In The Clowns" especially for Johns, who sang it in the original Broadway production of A Little Night Music.
"I always said that Send In The Clowns was the best gift I was ever given," she said.
Johns also made frequent TV appearances and starred in a short-lived US sitcom Glynis in 1963. She even played a villain, Lady Penelope Peasoup, in the popular Batman series in the 1960s. Her last acting role was in the 1999 film Superstar, starring Molly Shannon and Will Ferrell.
A member of a showbusiness family, Johns was born on October 5, 1923, in South Africa while her Welsh parents were performing there, and she took to acting as a child.
Johns had one son who predeceased her.
with AP
