British engineer who was formerly a military officer in the Royal Engineers. His father G.W. Mellis was Acting Superintendent of Works for St Helena (c. 1830) before becoming Surveyor-General for the East India Company and was latterly employed on the island by the British Government. He purchased the Oak Bank Estate on the island where he lived (c. 1846-1851). J.C. Mellis was also employed in St Helena by the colonial government, working on projects such as the restoration of Longwood House, Napoleon's home (1815-1821) during his exile on the island.
Melliss was made redundant (1871) following government retrenchment and returned to England where he founded the engineering firm of J.C. Mellis and Co., which was later merged to become Melliss and Partners and latterly Mellis LLP. J.C. Mellis was joined in his company by his son H.J. Melliss and they carried out civil engineering projects including familar landmarks such as water storage towers and Thames wharves. During the Second World War H.J. Melliss was involved with Operation Pluto (Pipe-Lines Under The Ocean) and the Mulberry Harbour project, both of critical importance to the D-Day landings.
During his stay on St Helena, J.C. Melliss was encouraged to take an interest in the natural history by Sir William Hooker and latterly by E. Sabine, T.V. Wollaston and others. On his return to England, Melliss published a landmark book which established him as the first historian of the island and included a section on natural history intended as a precursor for an ambitious broader study of the African islands of the southern Atlantic. The botanical illustrations for the floristic survey were by his wife. His book provides important documentary evidence of a unique flora under threat as it was being heavily modifed by the island's inhabitants and a number of species were in the process of becoming extinct. One species restricted to the drier parts of the island was Mellissia begoniifolia Hook. f. in the Solanaceae, a plant named in his honour. Until the discovery of a single plant in 1998 it was for long thought to be extinct and is currently represented by less than 20 individuals.
Melliss was interested in all aspects of natural history and a wide range of specimens were deposited at the Natural History Museum in London and with other organisations. The phanerogams were mainly identified at Kew with the assistance of J.D. Hooker and W.B. Hemsley, while cryptogams were identified by W. Mitten, W.A. Leighton, M.J. Berkeley and G. Dickie. In addition to pressed plants a number were spirit-preserved specimens, some of which were transferred from BM to K in 1983 including material of the extinct Trochetiopsis melanoxylon (R. Br. ex W.T. Aiton) Marais in the Sterculiaceae.
