Carl Pehr (Peter) Thunberg, Swedish physician and botanist, studied medicine and various other subjects at the University of Uppsala from September 1761. One of his fellow students was Anders Sparrman* while one of his teachers was the famous taxonomist Carl von Linne (Carolus Linnaeus the elder), whose system of classification Thunberg used throughout his career. He completed his medical thesis for the doctorate, entitled Dissertatio medica de ischiade (on sciatica), in June 1870 and received his licentiate in medicine, though the degree Doctor of Medicine was conferred upon him (in absentia) only two years later. In September 1770 he left Sweden to continue his studies in Paris, funded by a bursary, but first went to Amsterdam, the Netherlands. There he met the botanists J. Burman and his son, N.L. Burman, who were impressed by his knowledge of botany. He described some Cape plants in their collection that had been gathered by Paul Hermann* and H.B. Oldenland*. During a stay of six months or more in Paris he attended lectures and visited various libraries, medical establishments, botanic gardens and natural history collections, returning to Amsterdam in July 1771. Burman and his son arranged sponsorships that would enable him to go to the Cape of Good Hope and Japan to collect plants and other natural history specimens, travelling as a surgeon on one of the Dutch East India Company's ships. He would first stay at the Cape for some time to collect plants and learn Dutch, as the Dutch were the only Europeans allowed limited access to Japan at the time. In his first scientific paper, published in 1773, he described the effects of accidental lead poisoning, from which he and the ship's officers suffered on the journey to the Cape.
Thunberg arrived in Table Bay on 16 April 1772 for a stay of three years. Upon arrival he met his Uppsala colleague, Anders Sparrman*, who had arrived only a few days earlier. Initially he collected in the vicinity of Cape Town and was greatly interested in the Company's garden, where he met J.A. Auge*. With Auge as his guide he set out on his first journey into the interior on 7 September 1772. They collected near Mamre for a week before travelling to Saldanha Bay. From there they turned east, followed the Berg River past the Piketberg, and crossed the mountains towards Roodezand (Tulbagh). After collecting in the vicinity for two weeks they continued south-eastwards and followed the Breede River to Swellendam. From there they travelled east via Mossel Bay and Knysna to Plettenberg Bay. In the Knysna forests the party was attacked by a buffalo which killed two of their horses. They continued north over the Outeniqua Mountains to the Langkloof, and then east as far as the Gamtoos River. On the return journey they kept north of the Outeniqua mountains and the Langeberg, crossed the latter at Plattekloof near present Heidelberg, and arrived back in Cape Town on 2 January 1773. That same month Thunberg met the French naturalist Pierre Sonnerat*, with whom he collected plants and birds while they resided together at the farm of Mr M.A. Berg, secretary of the Council of Policy, near Constantia. Among their many excursions they climbed Table Mountain (which Thunberg did fifteen times during his three year stay). He was also sometimes accompanied by Captain (later Colonel) R.J. Gordon*.
On 11 September 1773 Thunberg set out on his second journey, this time accompanied by Francis Masson*. As on the first journey they first travelled to Salhdanha Bay, but from there went to collect in the Cold and Warm Bokkeveld. Following a similar route as on the first journey they travelled via Swellendam to Mossel Bay, then crossed the mountains via Attaquas Kloof (now Robinson Pass), and travelled east through the Langkloof and continued eastwards as far as the Sundays River. He arrived back in Cape Town on 28 January 1774. One of the persons he met in Cape Town this year was Lady Anne Monson*.
Waiting for spring again Thunberg set out on his third and last journey, again in the company of Masson, on 29 September 1774. They climbed the Paardeberg, Riebeek Kasteel and Piketberg, followed the Verlorevlei to Elandsbaai, crossed the Olifants River and via the Gifberg (near present Van Rhynsdorp) reached the Bokkeveld Mountains. After ascending the plateau they explored botanically unknown territory in the Roggeveld. After descending to the lower country via Verlaten Kloof they went on to Verkeerde Vlei, via the Hex River Pass to Roodezand, and were back in Cape Town on 29 December 1774. He was the first private visitor to travel far into the interior, but his account of his travels was published after those of Masson and Anders Sparrman*.
Leaving the Cape on 2 March 1775 Thunberg travelled to Batavia (now Jakarta, Indonesia) and from there to Japan, arriving at Nagasaki in August. Though his movements were restricted, he accompanied the Dutch legation, as their acting physician, on its annual visit to the Shogun's court at Edo (now Tokyo). He returned to Batavia in January 1777, where he remained until July. After a visit to Ceylon he arrived at the Cape on 24 April 1778. There he met the plant collector William Paterson*, before leaving for the Netherlands on 15 May. After a few months he went to London, where he met Sir Joseph Banks* and other prominent botanists. He returned to Sweden in March 1779. During his absence, in May 1777, he had been appointed demonstrator of botany at the botanical gardem of the University of Uppsala. He was promoted to associate professor of botany in 1781 and in 1784 succeeded the younger Linnaeus as professor of medicine and botany, a post he held to his death. Also in 1784 he married Brigitta C. Ruda. They had no children of their own, but adopted a son and a daughter.
Thunberg undertook no further major travels. He continued to work on his collections and publish during the rest of his carreer. His travels were described in a four volume work (Uppsala, 1788-1793), which was translated into German, French and English, the latter entitled Travels in Europe, Africa and Asia, made between the years 1770 and 1779 (London, 1793-1795). It contained a detailed account of his experiences, with numerous notes on the botany, geology, hydrography and weather of the regions he visited. The first two volumes include his travels at the Cape, the third deals with Japan, while the fourth covers his visit to Britain. Among others he provided a short account of native medicines and Dutch folk medicine at the Cape, mentioning the uses of a number of medicinal plants and animal products. A revised English translation of his Cape travels was later published by the Van Riebeeck Society (Forbes, 1986).
Thunberg was the first professional botanist who personally made extensive collections of South African plants and studied them at first hand. During his three year stay at the Cape he collected over 3000 plant species, of which more than 1000 were new to science. He was an extremely thorough and painstaking collector, as shown by the fact that several of the remarkable plants that he described were later missed by other thorough collectors such as C.F. Ecklon*, C.L.P. Zeyher* and J.F. Dr?ge*. Although much of his material was enumerated in his own publications, many specimens were provided to colleagues for study. Initially he publlished his Prodromus Plantarum Capensium, quas, in Promontorio Bonae Spei Africes, annis 1772-1775, collegit in two parts (Uppsala, 1794, 1800), but this was little more than a brief descriptive catalogue. Subsequently he expanded it into his best known work, Flora Capensis, sistens plantas Promontorii Bonae Spei Africes..., which represented the first comprehensive treatment of the Cape flora and remained the standard text on the subject for nearly a century. It appeared in five parts between 1807 and 1820 and the whole work was edited by J.A. Schultes and published in Stuttgart in 1823. It enumerates no less than 3100 species. Included are 14 fungi and 39 lichens, the first significant collection of these groups to be recorded from South Africa. The main shortcoming of this work is that Thunberg ignored the substantial taxonomic literature relating to southern Africa that had been published by others from 1790 onwards. Meanwhile he had published approximately 200 other botanical papers and dissertations, the latter written in collaboration with students, many of which contained descriptions of new genera and species of Cape plants. Those dissertations in which new genera of plants were introduced were re-published in 16 volumes entitled Nova genera plantarum (Uppsala, 1781-1801). Among the more important plant genera from the Cape on which he published detailed taxonomic monographs were Protea (1781), Oxalis (1781), Ixia (1783), Gladiolus (1784), Aloe (1785), Erica (1785), Moraea (1787), Restio (1788), Hermannia (1794), Diosma (1797), Drosera (1797), Aspalathus (1802), and Phylica (1804).
Other papers by Thunberg dealt with animal life at the Cape, for example, short descriptions of five species of Cape finches (1784), two papers on Cape antelopes (1811), the original description of the brown hyena (1820), and a revision of the known South African mammals (1811). More importantly, between 1775 and 1827 he produced no less than 47 publications with descriptions of insects occurring in South Africa. Many of these appeared in the journals of scientific societies in Uppsala and St Petersburg, while others were separately published brief dissertations by students. For example, he described the Coleoptera (beetles) of the Cape in several papers in the Memoires de l'Academie Imperiale des Sciences de St Petersbourg (1813, 1818, 1820, 1821). Usually little information was provided about new species, which limits the usefulness of the publications for taxonomic purposes. In July 1785 he presented his herbarium of 23 500 specimens (representing 15 000 plant species) and collections of 25 000 insects, 6 000 shells, 300 stuffed animals and 1 200 birds to the University of Uppsala. He was appointed curator of the collection, so that it remained accessible to him during his lifetime.
Thunberg also published Flora japonica (Lipsiae, 1784), a critical and comprehensive work on the vascular plants of Japan that contained much new information and soon became an indispensable classic. More than 300 illustrations of his Japanese plants were later published by Y. Kimura and V.P. Leonov (eds) in C.P. Thunberg collection of drawings of Japanese plants... (Tokyo, 1994). Among his later publications (1825-1828) were five dissertations, each written by several students, on the animals and plants mentioned in the Bible, with references to contemporary knowledge. They dealt with amphibians and fishes, mammals, birds, insects, and plants respectively. He wrote mainly in Latin and Swedish, and many of his publications are now difficult to find.
Thunberg was famous and honoured the world over. He was a member of the Swedish Academy of Sciences for 56 years, serving as president in 1784. In addition he belonged to more than 60 other learned societies and corresponded with colleagues in many countries. In 1785 the Swedish king honoured him as a Knight of the Royal Order of Vasa, and in 1815 as a Commander of the same order. He was a generous person who cared deeply for others. His main scientific strength was his ability to observe and describe specimens accurately. Having laid the foundation of taxonomic botany in South Africa he is widely recognised as the "father of South African botany". The plant genera Thunbergia and Thunbergiella and many plant and animal species were named after him.