It’s really not a good idea to mess with Violet Weston, the fire-breathing dragon lady of Pawhuska, Okla., who presides over a feast of family combat in “August: Osage County.” As all who have seen Tracy Letts’s celebrated comedy-drama on Broadway no doubt vividly recall, Violet does not brook much interference when it comes to indulging her favorite pastimes.

Raise an objection to that eviscerating commentary on her daughter’s looks and you are likely to find your own being mercilessly dissected. Delicately suggest that she refrain from airing the family’s dirtiest laundry over dinner and you will be subjected to eyebrow-singeing bursts of invective.

Oh, and don’t even think of getting between Violet and the little bottles of pills she pops like Tic Tacs. That would be a sure way to lose a limb.

Violet is a maternal monster on an outrageous scale, but she is also one of the most spellbinding characters in memory to stalk a Broadway stage. So it is good news to report that Estelle Parsons, the venerable actress who has taken over this demanding role from the Tony Award-winning Deanna Dunagan, has had the good sense not to mess with her much.

All the hallmarks of Violet’s character — the implacable cruelty, the shrill self-pity, the wily manipulation and the will of iron — are present and accounted for in Ms. Parsons’s superb performance. But it is not a facsimile of Ms. Dunagan’s unforgettably astringent approach to the role; Ms. Parsons forges her own path into the tortured darkness of Violet’s drug-addled psyche.

She is a naturally more grandmotherly presence, with her incongruously warm smile and slightly dowdy frame. If Ms. Dunagan was a rattlesnake, Ms. Parsons is more of a snapping turtle. In the Parsons interpretation, Violet takes an almost childlike delight in drawing blood. Glints of pure pleasure dance in her eyes when she sees that a revelation or an insult has hit its target. And yet she almost seems to gape in wonder and surprise at the toads that keep leaping from her mouth. Golly, did I just say that?

In the brief oasis of calm that arrives in the play’s third act, when Violet has emerged from her drug-fueled reign of terror, Ms. Parsons shows us glimpses of the casually affectionate mother overtaken by the vengeful shrew. But when she relates to her three daughters a story that provides a grim portrait of her own savage mother, the utter lack of feeling in her account sends a chill down your spine.

Ms. Parsons has had a long career as an actress in film (“Bonnie and Clyde”) and theater, and has worked frequently as a director too (the semi-staged “Salome” with Al Pacino, seen on Broadway in 2003). She has also taught at the Actors Studio, of which she was the artistic director for five years.

But she has not been seen on Broadway much in recent years — a role in the 2002 revival of “Morning’s at Seven” was her most recent appearance — so her return in this lengthy part in an emotionally draining play is both exciting and almost unexpected. Ms. Parsons is, after all, 80. (Ms. Dunagan cited exhaustion in explaining her decision to take a breather before traveling to London with the show in the fall.)

But just as Violet’s endless reserves of bitterness seem to keep her young, the role’s demands must be inspiring for an actress of any age. The challenge of embodying this complicated, terrifying woman seems to burn away the years; if I didn’t know Ms. Parsons was 80, I would never believe it. I hope she’s having the time of her life. She is certainly giving a performance to remember, one that may prove to be a crowning moment in an illustrious career.

Ms. Parsons is just one of several additions to the cast of “August,” and it is a tribute to the attentive direction of Anna D. Shapiro that the production still has the taut intensity it displayed when it opened in December. The new performers — some imported from the Steppenwolf Theater Company in Chicago, where the play had its premiere — have been integrated seamlessly into what remains the most accomplished ensemble cast on Broadway.

As Mattie Fae, Violet’s bulldozer of a sister, Molly Regan turns down the volume a notch or two compared with the Tony winner Rondi Reed. But she locates all the wicked humor in Mattie Fae’s tactless needling of her son, Little Charles, now played with affecting simplicity by Jim True-Frost. (Both actors are Steppenwolf members.)

Robert Foxworth exudes a convincing sense of ancient resignation as Mattie Fae’s henpecked husband. His seething rebellion against her brutality is among the punchiest audience-rousing moments. Frank Wood (“Side Man”) slides comfortably into the role of another milquetoasty husband, the philandering spouse of Violet’s oldest daughter, Barbara. And Michael McGuire, who took over the role of Beverly Weston, the doomed patriarch, when the playwright’s father, Dennis Letts, became ill (sadly, he subsequently died), delivers the play’s opening monologue with a fine, weary lyricism.

More good news: the actresses in the roles of the Weston daughters have stayed with the production, lending a sense of continuity. All have subtly improved in the roles. Sally Murphy’s Ivy is more movingly forlorn, but quietly determined too. Mariann Mayberry’s Karen, the youngest and most nakedly needy sister, remains a bright blast of comic relief, safely this side of caricature.

And Amy Morton is simply towering in the all-important role of Barbara, the family anchor whom we watch sinking into cynicism and bitterness under the weight of her father’s death and her family’s disintegration. The colors in the role are all more saturated now — the withering sarcasm, the sense of anguished confusion at her husband’s betrayal, the grim rise to the challenge of her mother’s antagonism. But they are blended so delicately that the resulting portrait is as fine an example of the stage actor’s art as you could ever hope to see.