Jim Spellman / WireImage 1 / 11
Jim Spellman / WireImage 1 / 11

"American Horror Story" star Jessica Lange is no longer dating her longtime partner, playwright and actor Sam Shepard, the actress's rep confirms to Us Weekly.

PHOTOS: Biggest breakups of 2011

"They separated a little less than two years ago," a source adds of the Hollywood power couple.

Dating since 1982, Lange and Shepard have two children together: daughter Hannah, 26, and son Samuel, 24.

PHOTOS: Stars who haven't wed -- yet!

Prior to her relationship with Shepard, 68, Lange was married to photographer Francisco "Paco" Grande from 1970 to 1981. The same year they split, Lange welcomed a daughter, Alexandra, with dancer and actor Mikhail Baryshnikov.

PHOTOS: Are these stars better off single?

Lange, a two-time Oscar winner, was recently nominated for a Golden Globe award and a Screen Actors Guild award. She next appears in February's "The Vow" opposite Rachel McAdams and Channing Tatum.


Second-Chance Relationships

Shocking Celebrity Splits!

Oscar Couple Splits