Lutheran and Moravian missionaries collected the earliest botanical specimens from Greenland. More intensive floristic studies began early in the nineteenth century, with Danish exploring expeditions that included well-qualified botanists, notably Morten Wormskjold and J. L. M. Vahl. Later in that century, many Danish, Swedish, British, German, and American expeditions brought botanists to Greenland. After 1906, scholars based at the Disko Arctic Station, especially M. P. Porsild, contributed much to floristic knowledge. Botanists on Danish, Norwegian, and other expeditions during the first half of the twentieth century included Eugenius Warming, H. G. Simmons, and P. F. Scholander. From the 1930s to the present, botanists from the university and botanical garden at Copenhagen have conducted much research in Greenland, among them T. J. Sgrensen (founder of the Greenland Botanical Survey), T.