English botanist and entomologist from Bristol, who was an avid collector of cryptogams and became Secretary of the Botanical Society of London (1839). He was appointed Superintendent of the Peradeniya Botanic Gardens in Sri Lanka (1849), becoming the Director of the gardens (1857-1880). Thwaites founded what is now the Hakgala Botanical Garden as a site for quinine production from Cinchona, which he was responsible for introducing to Sri Lanka. He retired from his directorship, to be succeeded by Henry Trimen, and shortly afterwards died at Kandy. His original British herbarium was deposited at Clifton College in Bristol (CFN) but later transferred to BRIST; material at BRIST was destroyed during the Second World War. Original material from Sri Lanka and the Pacific is mainly at PDA and K, but some original cryptogamic specimens and perhaps some British material were transferred from K to BM under the terms of the Morton Agreement after 1961.