\”The Syringa Tree,\” which won the 2001 Obie Award for best play and premieres in Los Angeles this week, might be the first theatrical work to deal with the complicated and ambiguous relations between Jews and blacks in South Africa. A solo performance written and acted by Pamela Gien, it is a partly fictionalized — though mostly factual — account of a half-Jewish, half-English child in Johannesburg during apartheid. Created by Gien in a Santa Monica acting class in 1996, the play was inspired by the brutal murder of Gien\’s grandfather when she was a child.