In this gouache created in 1526 (!), Albrecht Dürer depicted the plants exactly as he saw them growing in the field. It was a unique approach at that time. His observations would have a lasting influence on the rendering of flowers in art well into the 17th century.
Only ten of Dürer’s studies of plants survive. The humanist scholar Conrad Celtes compared Dürer's work to the literary work of the medieval philosopher and scientist Albertus Magnus who also based his work on the observation of nature. A realistic representation of nature was not a goal in itself for Dürer, but simply a tool for better conveying the sacred messages of his greater works. Tuft of Cowslips was primarily a study that would help him in the development of his art. The results can be seen both in his paintings, and in his highly detailed engravings.
P.S. Here are 7 images of Dürer’s animals that are better than a trip to the zoo!