John Hunter McLea, a horticulturalist, emigrated to the Cape of Good Hope from Scotland in the late 1850's and settled in Graaff-Reinet, where he started a forestry nursery. His interest turned to mosses and, encouraged by Dr Harry Bolus*, he dissected and made drawings of his specimens.
A municipal Botanic Garden was established in Graaff-Reinet in 1872, with both Bolus and McLea serving on its committee of management. McLea gave much of his spare time to lay out and develop the garden and was appointed as its Curator. By this time he had planted 850 trees and was planning to write a handbook of gardening, which seems not to have been completed.
Having met President T.F. Burgers of the South African Republic (Transvaal) in Graaff-Reinet he decided to move to the Transvaal with his family, leaving in February 1873. They travelled via Kimberley to Pretoria and on to the goldfields around Lydenburg and Pilgrims Rest. McLea was one of the first plant collectors there, others being Dr W.G. Atherstone* and Christopher Mudd*. (These three were also the first significant collectors in the Transvaal as a whole after C.L.P. Zeyher* and J. Burke* some 40 years earlier).
Returning to Pretoria towards the end of 1873 McLea was appointed late in 1874 to lay out a botanic garden on the site of present Burgers Park. A committee of eight prominent citizens was appointed to oversee the project. In March 1875 he submitted proposed regulations pertaining to the Botanic Garden to the government. By May he had planted flowers and vegetables and grown thousands of young trees from seed. However, no provision had been made to ensure a regular supply of labour for the garden, with the result that the work progressed slowly. Furthermore, in May 1875, while President Burgers was absent, the Volksraad failed to approve McLea's contract. He offered to be transferred to the Public Works Department, but nothing came of it. Public meetings were then held to raise money for his salary, as he was regarded by the committee and the public as a thoroughly competent, practical and hard-working curator. In August he received 484 packets of flower, shrub and tree seeds from the Royal Botanical Gardens at Kew, England, and continued to develop the garden as fast as the available labour allowed. But without an official contract and support his position was untenable and he resigned in September 1875. He was succeeded by Otto Lincke*.
McLea returned to Graaff-Reinet and to the curatorship of the Botanic Garden there at a salary of 200 pounds per year, indicating the high esteem in which he was held. He held this post from 1876 to 1878, when he died of a stroke while at work in the garden. He was succeeded by William Tuck*. McLea was married to Margaret Haddow McLea, born Hunter, with whom he had three sons and four daughters. He should not be confused with his eldest son, also named John Hunter, who was born at Graaff-Reinet in 1861, became an accountant, and was on the Witwatersrand shortly after the discovery of gold there in 1886.
Plants collected by McLea were bought by Harry Bolus and are in the Bolus Herbarium of the University of Cape Town, while some duplicates of his flowering plants are in the National Herbarium in Durban, the Compton Herbarium in Cape Town, and at Kew Gardens. A collection of his mosses and a few lichens collected at Lydenburg were acquired from Bolus by Dr Anton Rehmann*; the rest of his mosses are in the Bolus Herbarium and in the herbaria of the British Museum, Albany Museum, and National Botanical Institute in Pretoria. A number of lichens collected by McLea in the Cape and Transvaal were described by James Stirton in the Transactions of the Glasgow Society of Field Naturalists in 1877. McLea was commemorated in the species names Sutera macleana and Pterygoneurum macleanum.