Flowers such as four-o'clocks and portulacas invented the fluorescent look long before the psychedelic 1960s with its black light posters, new research shows.
These species rank as the first flowers found to fluoresce naturally in people's visible-light range, says Fernando Gandía-Herrero of the University of Murcia in Spain. Some other plant pigments emit fluorescent light in the ultraviolet range.
The yellowish pigments that give the visible glow are called betaxanthins. These pigments show up in four-o'clocks (Mirabilis jalapa), portulacas, and certain other flashy flowers