The tuberose (Polianthes tuberosa) is a garden plant of the agave family, Agavaceae. The tuberose is not related to the rose.
It is a night-blooming plant that is believed to be native to Mexico, but can be found in various locations today. It has waxy white flowers and is used in perfumery.
Further information about the tuberose in Crivelli’s pictures could not be found.
For more information about the tuberose see:
Bibliography:
"tuberose." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 29 Jan. 2014 <http://www.encyclopedia.com>.
"Tuberose." Interflora. Interflora British Unit, n.d. Web. 29 Jan. 2014. <http://www.flowers.org.uk/flowers/flowers-names/q-t/tuberose/>.