In the description and on the old plate, this rose is described and pictured as dark-red. However all the photo's are of a pinkish bright "red" flower. I doubt whether that those photographed roses are the original 'François Arago'
Difficult to say. You know how difficult it is to get the correct red tone when making photos. There seem to be 2-3 different roses pictured, and I am comparing the sepals with the plate from Flore des Serres: the rose at Labenz has similar long leafy sepals, Marita Protte's rose has short sepals, Loubert's rose does not seem full enough. I wish we had a photo ex Sangerhausen to compare with.
