What type of category does Echium and Oxydendrum have in common?
Echium Echium is a genus of 60 species of flowering plant in the family Boraginaceae.
Ecballium Ecballium is a genus of flowering plants in the family Cucurbitaceae containing a single species, Ecballium elaterium, also called the squirting cucumber or exploding cucumber (but not to be confused with "Cyclanthera explodens"). It gets its unusual name from the fact that, when ripe, it squirts a stream of mucilaginous liquid containing its seeds, which can be seen with the naked eye. It is thus considered to have rapid plant movement.