Which has more species, Thunbergia or Eriostemon? 
Thunbergia:  "Thunbergia" species are vigorous annual or perennial vines and shrubs growing to 2-8 m tall. Eriostemon:  It is native to eastern Australia and includes just two species, "Eriostemon australasius" and "Eriostemon banksii".
i don't know