British botanist Katharine Horner was the fourth in a family of six daughters born in London to geologist Leonard Horner and his wife Ann. She grew up in a science-oriented family – her father sometimes brought his daughters with him to meetings of the British Association for the Advancement of Science. At a visit to her sister, Mary, who was married to the eminent geologist Charles Lyell, she met his brother, Henry, and married him in 1848. She traveled to India with her husband and collected plants in the Ganges Delta as well as in Assam and the Khasia Hills ; she gave the specimens to the British Museum. Her special interest was ferns, and in 1870 she wrote the “Geographical Handbook of All the Known Ferns”; she donated her own collection of ferns to the Royal Botanical Gardens at Kew. In 1881, after her sister Mary died, she edited the two-volume “Life and Letters of Sir Charles Lyell.” In 1906, she undertook another two-volume editing job: editing the life and letters of another brother-in-law, Sir Charles J.F. Bunbury, husband of her sister Frances.