NEW YORK — Elaine Kaufman, who became something of a symbol of New York as the salty den mother of Elaine’s, one of the city’s best-known restaurants and a second home for almost half a century to writers, actors, athletes and other celebrities, died Friday in Manhattan. She was 81.

Her death, at Lenox Hill Hospital, was caused by complications of emphysema, said Diane Becker, the restaurant’s manager.

To the patrons she knew at her Upper East Side establishment, Kaufman was the quirky, opinionated, tender-hearted and imposingly heavyset proprietor who came in almost every night to check on things and schmooze, moving from table to table and occasionally perching herself on a stool at the end of her 25-foot mahogany bar.

With those she did not know, her demeanor varied; some accused her of being rude, though she indignantly denied that she ever was. As she put it, she had little time to explain to dissatisfied customers why they were being directed to tables in the back, known as Siberia, or led to the bar or even turned away, when they could clearly see empty tables along “the line.”

The line was the row of tables along the right wall of the main room, extending from the front to the back and visible from the entrance. Those tables were almost always saved for the most valued regulars, with or without reservations. One regular was Woody Allen, who filmed a scene for “Manhattan” at Elaine’s.

Elaine’s flourished, despite its less-than-stellar reputation for food. For 14 years, it was the site of the New York Oscar-night parties hosted by Entertainment Weekly. “I live a party life,” Kaufman said in an interview in 1983 in The New York Times. “Elsa Maxwell used to have to send out invitations. I just open the door.”