S. caeruleus is Prof. Bellstedt’s favorite, on account of its elegantly formed and bright flowers. A closer view of the flowers better illustrates this elegant and unusual form.
The flowers of the species have been described as “violet blue”, with some individual plants exhibiting magenta flowers. It seems from this photo that the specimen is from the latter kind of plants, although it is possible that the the flower color is an artifact of the film used and the lighting conditions.