Although von der Decken failed to reach Mount Kilimanjaro's summit, his and Richard Thornton's data ended the debate as to whether there was any settled snow or ice in tropical Africa. During his 1862 expedition, von der Decken also became the first European to record a sighting of Mount Meru, located forty or so miles to the west of Mount Kilimanjaro. These achievements, together with his descriptions of the area - including that of the bird subsequently named after him, the Von der Decken's hornbill - earned von der Decken the Patron's Medal of the Royal Geographical Society in 1864. Lobelia deckenii, a species of giant lobelia native to the East African mountains, was also named after him.