Pictured on the incandescent backdrop of Anna Sui’s spring runway was a single home amid a rolling field of wheat. Or a little house on a prairie. Yes, this was Sui’s paean to the heartland. The girls emerged as youthful free spirits cast in dusky sepia tones — faded blues, ruddy browns and lilac — that traced back to the Terrence Malick film “Days of Heaven.” Sweet pioneers came in patchwork prints, cowboy plaids, suede pinafores and chambray rompers paired with boots and feathered headbands. Not one for a singular influence, Sui loaded her paisley silk baby dolls and handkerchief-hemmed skirts with a multitude of kindred corn-fed references, from Joni Mitchell to Holly Hobbie. There were folksy cardigans crocheted with rainbows and clouds and doily shorts. A brief dark streak of witchy-woman dresses aside, the collection radiated sunny American beauty.