John Sanderson, journalist, trader, politician and plant collector, was educated in Glasgow and on the European continent and worked as a journalist in Scotland. He emigrated to Natal in March 1850, where he was involved in a failed business venture with his brother. The next year he became secretary of the newly established Natal Times Company and a regular contributor to that paper. In November 1851 he left on a trading and plant collecting trip, travelling via Harrismith to Mooi Rivier Dorp (now Potchefstroom) and after spending about a month in the vicinity of Rustenburg returned to Natal via the Witwatersrand in April 1852. Upon his return he wrote a "Memoranda of a trading trip into the Orange River (Sovereignty) Free State, and the country of the Transvaal Boers, 1851-1852" which was published in the Journal of the Royal Geographical Society (1860). The same journal published his "Notes to accompany sketch maps of the Zulu and Amatonga countries and of the country between Aliwal North and Natal" (1862).
Sanderson played a prominent role in local and political affairs in Natal. He served on the Durban town council during 1855 and 1867-1869, and helped to write the city's first municipal bye-laws. He represented Durban in the Natal Legislative Council during 1862 and 1870-1872, and was a committee member of the Durban Political Association (1871). From about 1874 he served on the committee of the Durban Mechanics Institution, which provided library facilities and a reading room, and when it became the Durban Public Library in 1880 he was a member of its first committee. In 1856 he became a foundation member of the local Chamber of Commerce and served as one of its directors to 1880.
In 1876 Sanderson and P. Davis became owners of the Natal Colonist and Herald newspaper and two years later Sanderson became its sole owner. He often expressed extreme views in his newspaper articles. Argumentative and domineering by nature, he rigidly adhered to his views and attitudes. The newspaper foundered in 1880 owing to lack of support.
Sanderson's principal scientific interest was in botany, probably as a result of his association with M.J. McKen*. In July 1851 he became a member of the committee of the Natal Agricultural and Horticultural Society (founded in 1848) and by 1852 he was its corresponding secretary. He served as its president from 1860 to 1881. During this time he was generally of the opinion that the society's botanic garden was mismanaged and despite his respect for McKen's knowledge of the local flora the two had an uneasy relationship. Sanderson also served on the committee of the Durban Horticultural Society during 1868-1871. He corresponded with W.H. Harvey* in Dublin and with Sir W.J. Hooker, the director of the Royal Botanical Gardens at Kew, and supplied them with dried plants, seeds and bulbs over a period of 30 years. Harvey acknowledged his contribution of "very interesting and valuable collections from the Natal Colony and from Transvaal, containing many new genera and species", in the preface to Volume 1 of the Flora Capensis (1860) and in the second edition of his Genera of South African plants (1868), while McKen (1870) mentioned him as one of Natal's principal early fern collectors. Sanderson also corresponded with G. Walker Arnott, professor of botany at the University of Glasgow, who sent him directions for collecting diatoms in a letter dated 2 November 1859.
Sanderson wrote "Rough notes on the flora of Natal", which was published as an appendix to James Chapman's* Travels in the interior of South Africa (1868). In March 1868 he was present at the inaugural exhibition of the Natural History Association of Natal, where he exhibited 12 maps illustrating South African ethnology and geography. He served on the society's first council and at two subsequent meetings lectured on orchids. Around this time he sent at least 80 different species of orchids to Kew Gardens and became the colony's resident expert on this group. An article by him on the Natural History Association of Natal, "The study of natural history and the association for its promotion" was published in the Natal almanac and yearly register for 1869 (pp. 60-66). Later he became a member of the Natal Microscopical Society, founded in 1878, and reported on most of its early meetings in the Natal Colonist.
Sanderson was an accomplished artist. A large collection of his sketches and cartoons are housed in the Durban Local History Museum, a notebook with pencil sketches in the National Botanical Institute, Pretoria, and another collection of botanical sketches at Kew Gardens. The genus Sandersonia (fam. Liliaceae) was named after him by W.J. Hooker in 1853. Its single species, Sandersonia aurantiaca, or Sanderson's Christmas bell, was discovered by Sanderson in 1851. Other species named after him include Ceropegia sandersonii and Lissochilus sandersonii (by J.D. Hooker*), Cissus sandersonii (by Harvey), and Brachystelma sandersonii (by N.E. Brown*). Specimens collected by Sanderson are housed at Kew Gardens, the Botanical Research Institute in Durban, and the Compton Herbarium in Cape Town.
Another of Sanderson's interests was prehistoric stone artefacts. In 1878 he contributed "Notes in connection with stone implements from Natal" to the Journal of the Anthropological Institute, in which he described artifacts from various places in the colony and speculated about their possible functions.