Cullum (On the Twentieth Century, Shenandoah, Urinetown) will play patriarch Beverly Weston, whose disappearance launches the family reunion of the dysfunctional Weston clan of Oklahoma. Cullum had played eight performances in the role in September while Michael McGuire was on vacation.

The Broadway production played its 400th performance on Nov. 8 at 2 PM.

Also joining the cast Nov. 11 at the Music Box are Lortel Award nominee Amy Warren (the memorably dour co-worker Miss Devore in Off-Broadway's Adding Machine) as youngest daughter Karen Weston, and Broadway newcomer Samantha Ross as Native American housekeeper Johnna Monevata.

The company also includes Estelle Parsons as Violet, Johanna Day As Barbara, Frank Wood as Bill, Madeleine Martin as Jean, Molly Regan as Mattie Fae, Robert Foxworth as Charlie, Brian Kerwin as Steve, Michael Milligan as Little Charlie, Dee Pelletier as Ivy and Scott Jaeck as Sheriff Deon Gilbeau.

* Cullum won Tonys for Shenandoah and On the Twentieth Century and was nominated for On a Clear Day You Can See Forever and Urinetown. Off-Broadway, he was Drama Desk-nominated for Sin. Other Broadway credits include Camelot, 1776, Doubles, All My Sons, Old Money, Hamlet (Laertes, with Richard Burton), Boys in Autumn, Trip Back Down, Man of La Mancha and Show Boat.

Ross' Off-Broadway credits include Romeo and Juliet, A Midsummer Night's Dream, Pieces Of Ass, War W/The Newts. She is a graduate of New York University's Tisch School of the Arts Graduate Acting Program.

	Samantha Ross and Amy Warren

Warren also makes her Broadway debut with August. Last season, she appeared in the critically acclaimed Off-Broadway hit Adding Machine, for which she received Drama Desk, Outer Critics Circle and Lucille Lortel nominations for Best Supporting Actress. A Chicago mainstay, she has previously appeared with Steppenwolf in When the Messenger is Hot (at 59E59), Mother Courage and Her Children, House of Lily, The Weir and Whispering City. At the Goodman Theatre, she has appeared in Rabbit Hole, Heartbreak House and Trojan Women, among others. Directed by Tony, Drama Desk and Outer Critics Circle Award winner Anna D. Shapiro, August: Osage County is written by Tracy Letts.

A national tour will launch in summer 2009. The Shapiro-directed London production begins Nov. 21 at the National Theatre, with many of its original cast members.

August: Osage County performs Tuesday-Friday at 7:30 PM, matinees on Wednesday and Saturdays at 2 PM, Saturdays at 8 PM and Sundays at 3 PM.

Tickets can be purchased at Telecharge.com, or by calling (212) 239-6200. Outside the NY Metro (800) 432-7250.

The Music Box Theatre is located at 239 West 45th Street.

Visit augustonbroadway.com.