Does Centaurium or Eucalyptus have more species?
Centaurium: Centaurium (Centaury) is a genus of 20 species in the gentian family (Gentianaceae), tribe Chironieae, subtribe Chironiinae. Eucalyptus:  Members of the genus dominate the tree flora of Australia, and include "Eucalyptus regnans", the tallest known flowering plant on Earth.
i don't know