Polysiphonia nigrescens c. 1843 - 1853

"Polysiphonia nigrescens" is a cyanotype photograph of a seaweed by Anna Atkins, created between 1843 and 1853. Atkins was a pioneer of photography, and her work is considered to be among the first examples of photo-botanical art. The cyanotype process, which uses light-sensitive iron salts, produces a distinctive blue background with white details, showcasing the delicate structure of the seaweed in intricate detail. This particular image is a part of Atkins' groundbreaking book, "Photographs of British Algae: Cyanotype Impressions," a collection of cyanotype prints that revolutionized botanical documentation.