A close copy of this series of flowers in a Wanli vase, possibly by Jan Brueghel the Younger (Copper, 48 x 35 cm), is in Madrid, Museo del Prado, #1421. There are a number of further copies in private collections.
Brueghel usually painted his flowers directly from nature, without using drawings or sketches.
There are hardly any preserved flower sketches done by him, while landscape drawings remain in infinite supply.
He traveled to Brussels frequently, to study and paint rare flowers in the Archduke’s garden.