John Clayton, a plant collector in Virginia sent him many specimens in the 1730s, as well as a manuscript description. Without Clayton's knowledge, Gronovius used the material in his Flora Virginica (1739-1743, 2nd ed. 1762).
In 1737 Gronovius described the Transvaal daisy, naming it Gerbera.
His son Laurens Theodoor Gronovius was also a botanist.