Polysiphonia atro–rubescens [= Polysiphonia atrorubescens] c. 1843 - 1853

Anna Atkins, a pioneer in photography, created this cyanotype print of a seaweed specimen, *Polysiphonia atro-rubescens*, as part of her book *Photographs of British Algae: Cyanotype Impressions*. Atkins' work is significant for its contribution to both botany and photography; she used the cyanotype process to capture the intricate details of algae, making her a pioneer in the field of photo documentation. The blue background and white algae are characteristic of the cyanotype process, a technique that was popular in the early days of photography.