When looking through the 607 "Sunflower" images at Acclaim Images.com this Black-eyed Susan and Sunflower Blossoms in Halftones was a favorite.
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Description:
Black-eyed Susan and Sunflower Blossoms in Halftones
Stock image of black-eyed susan flower and sunflower blossoms. Extracted to white background then filtered to half-tones leaving image that appears like a negative.

Some related terms for more images:
summer flowers,  yellow,  sunflowers,  beth conant,  black and white,  black eyed susans,  bw,  blossoms,  halftone,  halftones,  filtered,