Silybum marianum (Woolly Thistle)with Vanessa atalanta (Red Admiral) and Pontia daplidice (Bath White); and Prunus cerasus (Cherry Blossom) with Argynnis lathonia [a] (Queen of Spain Fritillary) and Callimorpha dominula (Scarlet Tiger) [b]

There is still confusion between the work of Barbara Regina Dietzsch, her younger sister Margareta Barbara and their brother Johann Christoph. It has been suggested that the watercolour of the thistle (a) compares closely to watercolours signed by Johann Christoph in the Fitzwilliam Museum (see D. Scrase, Flowers of three Centuries, Washington, 1983, p. 18, pl. 23), and that the cherry blossom (b) is more likely to be by either Barbara or Margareta.

Johann Israel Dietzsch (1681-1754) had seven children who became artists. The Dietzsch family worked in Nuremberg, which, in the 18th century was the largest centre of botanical art outside London, thanks to the patronage and passion of Dr. Christoph Jakob Trew (1695-1769). Trew was a wealthy physician and one of the earliest patrons of Georg Dionysius Ehret (1708-1770). Barbara, Margareta and Johann were all employed at the Nuremberg court, where they painted botanical subjects, often for engraving. Johann was also known as a talented landscape artist.

A characteristic of the Nuremberg School and the work of the Dietzsch family was the use of an intense, dark prepared ground that enabled the artists to capture with minute precision botanical details such as stamen and, as we see in the above watercolours, the cottony hair that grow from the pappus of the thistle and the delicate tips of the spiney flower head.

The pen and ink key on a separate sheet enclosed in the frame is very close in style to the work of Thomas Robins, Jun. (1745-1806).