West Linn High School Theatre Arts Program’s musical “Little Shop of Horrors” opens tonight, at 7p.m. The show is based on a comedy film released in 1960, and its subsequent Broadway and film adaptations, about a florist’s assistant who grows a plant with a taste for human flesh.  Admission is $8 for students and $10 for adults, other performance dates are Feb. 24 and 25 and March 1, 2 and 3, also at 7p.m.