John Buchanan (1819-98) was bom in Dumbartonshire, Scotland, on 13 October 1819. He attended the parish school and was then apprenticed to a pattern designer at a print and dye works. This led him to study plants as a source for design material, and botany became a life-long interest. Buchanan moved to Glasgow, then at the age of thirty-two he left for New Zealand. He arrived at Port Chalmers, Dunedin, on the Columbus on 7 February 1852.

Employment opportunities were few in the early years in Dunedin, and for a short time John Buchanan tried his luck in the goldfields of Victoria, Australia. By 1856, however, he had purchased a small farm of twelve acres on Mt Cargill and within a year he was employed by J. T. Thomson, the Provincial Surveyor, on a reconnaissance survey. The object of the survey was to provide a general map as a starting point for farm settlement. A pencil sketch, "Taieri bush at Saddle hill", now in the Alexander Turnbull Library, is one of several sketches he made of inland Otago during the survey. In 1858 John Buchanan found gold in the Manuherikia River, which runs through Alexandra, and, a few weeks later, in the Tuapeka region, but he was unsuccessful in securing a share of the reward for the first discovery of gold in Otago.

John Buchanan's subsequent career is linked with that of Dr (later Sir) James Hector (1834-1907). Hector completed a degree in medicine at Edinburgh University (1856), where he also attended lectures in natural science. For several years he worked as a surgeon and geologist on a British Government expedition under Captain John Palliser, which had the task of exploring and mapping western Canada and seeking passes over the Rockies. James Hector discovered Kicking Horse Pass, which the Canadian Pacific Railway crosses. The pass was named after an accident which nearly killed Hector. In fact, it was said that his men were about to bury him when he blinked. Ironically, when James Hector returned to Canada in 1905, for the unveiling of a monument in his honour, his son died at Kicking Horse Pass from pneumonia.

After completing his work in Canada (for which he received the page 87 C.M.G.), Hector accepted the position of geologist to the Provincial Government of Otago and arrived in New Zealand in April 1862. Before James Hector left England, Sir Joseph D. Hooker, who succeeded his father as director of the Royal Botanic Gardens, Kew, asked him to "look out for a man called John Buchanan, who sent home to the herbarium at Kew the best collection of plants that were received from Australasia". Buchanan's collections were of considerable value to Hooker for the preparation of his Handbook of the New Zealand Flora (1867). Hooker told Hector that he considered John Buchanan would be an ideal person for him to employ for his geological survey work. Soon after arriving in Dunedin, Hector therefore advertised for Buchanan, they met, and he appointed him draughtsman and botanist.

John Buchanan was certainly ideally suited to the position. Although he had received little formal education, he was intelligent, resourceful, a very talented artist, and a strong man with an ability to handle horses, which was so important to the work of the Geological Survey of Otago. Early in 1863 Hector, Buchanan and four other men made their famous journey westwards to Lake Wanaka. In May of that year Hector and eight others left Dunedin on the Matilda Hayes and explored the sounds of the southwest coast of the South Island. Then, north of the sounds, they anchored in Lake McKerrow, a short distance up-river from the sea. Hector's party travelled inland to Lake Wakatipu. In the meantime John Buchanan had journeyed overland from the east coast and he joined Hector's party in Queenstown. They travelled through the Hollyford region and Lake McKerrow, then boarded the Matilda Hayes for the return trip. John Buchanan spent two very significant days in Milford Sound and made several pencil sketches and a watercolour. From some of these he later painted his now-famous watercolour "Milford Sound looking North-West from the Freshwater Basin", which has been described as an early masterpiece in New Zealand landscape painting and is now in the Hocken Library, Dunedin. John Buchanan did not gain recognition as a landscape painter in his lifetime.

As well as sketching the landscape, drawing maps, geological sections, animal and plant fossils, John Buchanan sketched plants and made herbarium specimens. The results of his botanical work were summarised in an essay, "A Sketch of the Botany of Otago", which, together with the plant specimens he had collected, were displayed as part of the work of the Geological Survey of Otago at the 1865 New Zealand Exhibition in Dunedin. A second edition of "Sketch of the Botany of Otago" was published in the first volume of the Transactions of the New Zealand Institute (1868).

When James Hector's three-year appointment as provincial geologist expired in April 1865, he accepted the joint appointments of first director of the New Zealand Geological Survey and director of the newly formed Colonial Museum (now the National Museum) and Colonial Laboratory in Wellington. The establishment of these positions followed the change of the page 88 seat of government from Auckland to Wellington in late 1864. Hector's duties included being in charge of the Wellington Botanical Gardens (until 1891), meteorological observations and an astronomical observatory (established later), as well as being custodian of weights and measures and head of the Patent Office library! At the time he was the only qualified government scientist, and for a considerable time, he was the only medical doctor in government employment. He brought most of the Otago Geological Survey staff", including John Buchanan, to Wellington. By September 1865 the Colonial Museum building, which occupied land on Museum Street behind Parliament Buildings, was completed. In 1867 the New Zealand Institute Act set up an institute for the advancement of science and art, to which the Colonial Museum and Laboratory were transferred. James Hector became manager of the institute, as well as retaining his other positions. For thirty-five years he edited the Transactions of the New Zealand Institute (now Transactions of the Royal Society of New Zealand). John Buchanan served as artist and lithographer, and illustrated many papers in the first nineteen annual volumes.

Hector and Buchanan continued with field work, spending New Year 1866 at Russell, and the following summer in the Kaikoura mountains and on Mount Egmont. A paper, "Botanical notes on the Kaikoura mountains and Mount Egmont", appeared in 1867. In it, Buchanan was critical of the policy of burning in Marlborough: "Repeated burnings are evidently reducing the number of species of plants, and a country naturally arid from its geological nature, will by this treatment become, in time, positively barren." As for Mt Egmont:

Although all who go up do not collect plants, still many do, and probably no locality in New Zealand has been better searched. Plants have been passing to Britain from there through various channels for many years. All idea, therefore, of finding much novelty may be dismissed, and the result of the present expedition has proved that the botany of this isolated mountain was well ascertained previous to my visit.

Next summer there were exhausting and hazardous visits to fossil beds and coal deposits in Otago and Southland. After that most of Buchanan's field trips were less arduous. He became very familiar with the plants of the Wellington district, the Wairarapa and Nelson, and became the first botanist to observe the vegetation of the Three Kings Islands. Later he visited Campbell and Auckland Islands.

Buchanan wrote many papers on New Zealand botany. Some were published in the Journal of the Linnean Society (London), and in 1880 he was elected a fellow of the Linnean Society. He wrote some thirty botanical papers for the Transactions of the New Zealand Institute. Most described, in concise terms, new species of native plants. Others dealt with plants in particular regions, for example, the floras of the Wellington region, Kawau Island and Campbell Island. He was interested in native timbers, as a paper "On the durability of New Zealand timber, with suggestions for its preservation" indicates. Another paper, "On the Wanganui beds (Upper Tertiary)", compared fossil shells. He even contributed an article "On pseudo-scab and lung-worm in sheep".

The lithographs he made for early volumes of the Transactions covered a wide variety of topics. Volume two, for example, contains illustrations of whales, an eel, birds' nests, stones, whitebait, ships, plants, leaf anatomy of flax (Phormium tenax), maps and geological sections. In many instances he made lithographs from the drawings of others. His own botanical drawings were superb, the earlier ones in particular. Illustrations pasted in his scrap-books, culled from British publications, indicate that he admired the work of Walter and John Fitch (see chapters V, VI and XV) and his best work shares the fine qualities of these illustrators.

When John Buchanan retired in June 1885, he was awarded a year's leave on full pay. Dr Hector (who received a knighthood in 1887) presented him with a diploma of life membership of the New Zealand Institute, which was "handsomely illuminated by Messrs Bock and Cousins", publishers of the Featon's Art Album (chapter X). John Buchanan "was quite taken by surprise, and was in consequence too much moved to answer at any depth. He retired to North East Valley, Dunedin, for to him nothing could compare with the Otago vegetation for "brilliant freshness or varied colouring". Fourteen years later he died, on 18 October 1898, aged seventy-nine. A bachelor, he left his property to his brother Peter in Sydney. Sir James Hector, in a tribute, spoke of his valuable contributions to New Zealand botany and of his talents as "a great explorer, or, rather, wanderer", who had endured "much hardship in collecting specimens of geological interest, minerals, birds even, and certainly, above all things, plants." He referred to Buchanan's large collection of specimens, books, drawings and manuscript notes in Dunedin and added the hope that "a little better care would be taken of the collection until they reached a more enlightened age".