NEW YORK — Retail legend Bloomingdale’s has announced that, beginning this Fall, it will feature a store-in-store devoted solely to a specially commissioned collection of apparel made from Supima, the brand of ultra-premium, extra-long staple cotton grown only in the United States.

The partnership is set to launch here in September with the Supima store-in-store in Bloomie’s world-famous flagship here at 59th Street and Lexington Avenue, one of Manhattan’s top tourist and shopping destinations, followed shortly thereafter by the highly trafficked Bloomingdale’s in SoHo.

Exclusive to Bloomingdale’s, the Supima collection of unisex and men’s T-shirts, henleys, hoodies, and other luxury basics will then roll out to 16 other Bloomingdale’s stores across the country.

Supima, a specially grown cotton that has been proven by laboratory testing to be demonstrably softer and sturdier than ordinary varieties of cotton, has become synonymous with a casual, authentically American approach to luxury apparel and fashion made from Supima has become a staple of high-end magazines ranging from Lucky to British Vogue (which named Supima an essential ingredient to “the world’s best T-shirt”).

“This follows a pattern that has been established by other luxury fibers, such as Scottish cashmere or Italian silk,” says Buxton Midyette, the New York-based vice president of marketing for the Phoenix-based promotional association of cotton growers known as Supima. “It’s also a great time to highlight that America offers beautifully made basics that equal anything produced anywhere else in the world.”