Oscar de la Renta returned to 583 Park Avenue for his pre-fall collection, and revisited the lavish floral prints that so dominated the Spring runways. And why not? They're such a vital part of the designer's oeuvre, after all. The show opened with a boldly colored brocade jacket worn over a fitted sweater and a full, dirndl-like skirt. That silhouette predominated as he worked his way through tweed suits, silk ikat, and dip-dyed silk faille, and, for evening, taffeta dresses worn to the knee or full and floor-sweeping. But this was no one-note show: There were also slim skirtsuits, full trousers paired with hand-knit sweaters, and a pair of jewel-tone goddess dresses in hammered satin. All in all, it added up to 63 looks, a sign of just how seriously de la Renta takes his pre-fall business.