Van Houtte, 1854-55
This is a hybrid of what is now known as Sinningia douglasii. A print of S. douglasii can be seen here, a photo of the species here.
This is a double-wide print, twice the size of the usual antique print. It is particularly nice in that the overall habit of the plant is illustrated in the engraving to the right, and the leaf in the background. the print of S. douglasii is similarily structure, and was printed in the same edition of Van Houtte's Flore des Serres and des Jardins.