Umberto Giordano’s “Fedora,” an Italian opera about Czarist Russian exiles starring Placido Domingo in the role of Loris, will lead off L.A. Opera’s 1997-98 season Sept. 3. This, along with the inclusion of another rarity, Emmerich Kalman’s “Countess Maritza,” and a new opera by contemporary composer Daniel Catan, “Florencia en el Amazonas,” signals a more adventurous direction for L.A. Opera than has been the case in the previous two seasons.“Fedora” will be seen in a production that L.A. Opera has purchased from Milan’s La Scala. Soprano Maria Ewing sings the title role. “Florencia en el Amazonas,” an L.A. Opera co-commission with the Houston Grand Opera and Seattle Opera, opens Oct. 5 with soprano Sheri Greenawald assuming the role of Florencia. “Countess Maritza,” which opens Nov. 22, marks a rare L.A. Opera venture into the realm of Viennese operetta, as seen in a production borrowed from Santa Fe Opera. Film director Herbert Ross’ production of Puccini’s “La Boheme” will be revived for the first time Sept. 6, with Puerto Rican soprano Ana Maria Martinez singing Mimi, Greg Fedderly as Rodolfo, Rodney Gilfry as Marcello and, in most performances, Inva Mula as Musetta. Also due to be revived are two productions by British director Sir Peter Hall: His rendering of Richard Strauss’ “Salome” (Jan. 15, 1998) and a revival of Mozart’s “The Magic Flute” as designed by Gerald Scarfe.