Patricia E. Geissler (25 July 1947 – 28 March 2000) was a Swiss botanist and bryologist who made significant contributions to the study of liverworts and alpine plants.
She served as curator of cryptogams at the Conservatory and Botanical Garden of the City of Geneva for over two decades and was known for her work on the Index Hepaticarum.
[2] She developed an early interest in botany during her undergraduate studies, influenced by the lectures and field excursions of Professor Heinrich Zoller.
[3] Following the death of her predecessor Charles Edmond Bradlaugh Bonner, she became responsible for managing the collections of algae, bryophytes, lichens, pteridophytes, and gymnosperms.
[3] From 1986, Geissler held a teaching position at the University of Geneva, where she conducted lectures and courses in systematic botany and cryptogam flora.
[2] She was particularly concerned with environmental conservation, especially regarding the impact of ski slope development on mountain forests, hillside moors, and snow-bed vegetation.