Is there a flower called cassandra?

There is no flower specifically called "Cassandra." However, there is a genus of flowering plants called Chamaedaphne which includes the species Chamaedaphne calyculata, commonly known as leatherleaf. Some people might informally refer to this plant as "Cassandra" due to its botanical name.

If you're thinking of another flower, such as those in mythological or literary references, there might be a mix-up. The name "Cassandra" is more commonly associated with Greek mythology, where Cassandra was a princess of Troy with the gift of prophecy.