Following the Treaty of Nanking in 1842, in early 1843, he was commissioned by the Horticultural Society to undertake a three-year plant collection expedition to southern China.

Similar to other European travellers of the period, such as Walter Medhurst, Fortune disguised himself as a Chinese merchant during several, but not all, of his journeys beyond the newly established treaty port areas.

Not only was Fortune's purchase of tea plants reportedly forbidden by the Chinese government of the time, but his travels were also beyond the allowable day's journey from the European treaty ports.

Fortune employed many means to obtain plants and seedlings from local tea growers, although this was some 150 years before international biodiversity laws recognised state ownership of such natural resources.

The other reason for the failure in India was that the British preference and fashion was for a strong dark tea brew, which was best made from the local Assam subspecies (Camellia sinensis var.

A climbing white rose that he brought back from China in 1850, believed to be a natural cross between Rosa laevigata and R. banksiae, was dubbed R. fortuniana (syn.