Ms. Falkenhain, whose actor husband, Robert Gerringer, predeceased her, was 77. The cause of death was a heart attack, a friend said.
Ms. Falkenhain won Obies for her work with Off Broadway's Phoenix Theatre as The Woman in Green in Peer Gynt and Doll Tearsheet in Henry IV, Part 2. Among her other Phoenix credits in the late 1950s and '60s were Gertrude in Hamlet, The Beaux' Stratagem, She Stoops to Conquer, Dark Lady of the Sonnets, Lysistrata, The Power and the Glory, Androcles and the Lion and The Plough and the Stars.
For the New York Shakespeare Festival, she appeared in early Central Park productions of Romeo and Juliet, Othello, Two Gentlemen of Verona and Macbeth. She also appeared in The Marriage of Bette and Boo at The Public. The troupe earned an ensemble Obie citation.
She played Madame Dupont-Fredaine in the national tour of The Waltz of the Toreadors, which opened in 1957 at the McCarter Theatre and played Broadway's Coronet Theatre in 1958. Melvyn Douglas starred.
Her other Broadway credits include The House of Blue Leaves (1986), Once a Catholic (1979) and The Utter Glory of Morrissey Hall (1979). Among Ms. Falkenhain's stock credits are seasons with the Canal Fulton Summer Theatre in Ohio.
Ms. Falkenhain was born in Atlanta and graduated high school in Scotch Plains, NJ. She attended Carnegie Institute of Technology in Pittsburgh 1944-46 and New York University 1946-48. She married Robert Gerringer in 1950.
Her first stage appearance was in a Carnegie Tech staging of All's Well That Ends Well in 1944. From her college days, she found work quickly Off-Broadway and in summer stock.