Thomas Robertson Sim (25 June 1858 in Northfield, Aberdeenshire, Scotland – 23 July 1938 in Durban, Natal) was a botanist, bryologist, botanical artist and Conservator of Forests in Natal, best known for his monumental work The Forests and Forest Flora of the Colony of the Cape of Good Hope which appeared in 1907. He was the eldest of five children of John Sim (1824–1901), a noted bryologist and Isabella Thomson Robertson (1823-). Education and career Attended Old Aberdeen grammar school until 1873 and in 1874 was given special tuition at Marischal College, University of Aberdeen. In that same year he served as apprentice gardener in the Royal Horticultural Society's gardens in Chiswick. In 1878 he was appointed to the Royal Botanic Gardens at Kew where he received a training in botany under Sir Joseph Dalton Hooker. In 1879 he worked for a year in the Harvard University botanic gardens in Cambridge, Massachusetts. Here he was influenced by Asa Gray and George Lincoln Goodale. Subsequently, he worked for a year in the garden of Colonel Peabody of Milton, Massachusetts. Returning to Scotland in 1881, he assisted his father on the farm at Inchmark from 1884–1888. In 1889 he took up the post of curator of the King William's Town botanical garden. In September 1894 he became a Government Forester with the Cape Forestry Department and started work at Fort Cunynghame Plantation near Döhne. Within a few months he was promoted to Superintendent of Plantations in the Eastern Conservancy, and by 1898 to District Forest Officer with headquarters at King William's Town. In 1902 he established a forest department in Natal, and became its first Conservator of Forests in 1903, with headquarters in Pietermaritzburg. In 1907 he travelled to London as representative of the South African Products Exhibition. In 1908 he was asked to visit Portuguese East Africa and later wrote a report on forest utilisation, which appeared as Forest Flora and Forest Resources of Portuguese East Africa, which was lavishly illustrated with his own line drawings. In 1908 he ventured into the commercial world by setting up a nursery in Pietermaritzburg, and advising on tree planting and large-scale afforestation, also venturing into the timber and wattle-growing industries, being a founder member of the Wattle Growers' Association and Cedara College of Agriculture. He was elected F.L.S., F.R.H.S. and F.R.S.S.Afr. and in 1919 received an honorary D.Sc. from the University of South Africa.