The flower Georgia O'Keeffe famously enlarged in Black Iris is the iris. Painted in 1926, Black Iris is one of her best-known flower paintings and presents the blossom at an unusually close scale. O'Keeffe used enlarged floral forms to make viewers look carefully at shapes and structures they might otherwise overlook.
Her flower paintings became central to her public identity during the 1920s and 1930s. Works featuring irises, poppies, lilies, and other blooms often crop the subject so tightly that it approaches abstraction. O'Keeffe rejected simplistic claims that the paintings were intended as literal symbols of female sexuality, arguing that viewers should focus on the flowers themselves.
Black Iris is commonly identified as Black Iris III, a 1926 oil painting in the Metropolitan Museum of Art. The broader iris series is sometimes discussed alongside her other flower works, but the specific flower in the title and image is the iris.