Five petal rose
Five lobes on the five steps of a true pentagon, which Euclid constructs exactly (Book IV, Proposition 11). The next two plates set the pentagon of the geometers beside the pentagon of the workshop.
In the faith
The rose is a title of the Virgin Mary: Rosa mystica, the mystical rose, in the Litany of Loreto.
Sources
- Euclid, Elements IV.11
- Litany of Loreto