Arnold, Joseph (1782–1818)

English botanist. In 1818 he discovered the largest flower known, at Pulau Lebar, Sumatra. The plant, measuring nearly a metre across and weighing almost 7 kg/15 lb, was later named Rafflesia arnoldii by the Scottish botanist Robert Brown.

Arnold was born in Beccles, Suffolk. He showed a childhood interest in botany and published his findings in various magazines. After graduating in medicine in 1807 at Edinburgh University, he entered the navy in 1808. He sailed to Botany Bay as the doctor on a ship of female convicts in 1815. During this trip he made an extensive collection of insects, especially those from South America and Australia, although many were destroyed by a fire on board his ship The Indefatigable, on its return journey. He visited Java with the British colonial administrator Stamford Raffles, who subsequently invited Arnold to accompany him to Sumatra as a naturalist. Arnold died there of a fever in July 1818. His collection of shells and fossils was donated to the Linnaean Society.