Picnic, Griffin Theatre Company. In his opening-night curtain speech, Griffin coartistic director William Massolia noted that William Inge’s 1952 drama runs 90 minutes without intermission, whereas “his contemporaries Tennessee Williams or O’Neill or Arthur Miller…would keep you here three hours.”

True enough, but Massolia’s remark reveals the weaknesses as well as strengths of this chestnut about parochial prejudices and late-summer passion. Inge packs a lot of social commentary into his story of a drifter and the lonely women (and a couple of their menfolk) he encounters in small-town Kansas one Labor Day weekend. Inge also supplies plenty of graceful shorthand, avoiding the occasional belaboring windiness of the (more frequently produced) playwrights noted by Massolia. But he runs the risk of creating cliches instead of complex characters by writing so economically.

Jonathan Berry’s staging, though it boasts a fine ensemble overall, too often simmers when it should bubble. Josh Bywater as Hal, the himbo who causes the uproar, provides the requisite easy, swaggering sensuality. But Katie Flahive as Madge, an 18-year-old dime-store clerk, doesn’t quite convey the earth-shattering longings Hal awakens in her. Melissa Riemer shines as Mrs. Potts, the resolutely nonjudgmental neighbor who first takes Hal in as a handyman, and Penny Slusher wins our sympathy in the potentially thankless role of an “old maid” schoolteacher awash in jealousy at Hal’s attentions to the lissome Madge.