What is the difference between Lobelia and Alyssum?

The difference between lobelia and alyssum is that "lobelia" is a member of the genus Lobelia, flowering plants in the Lobelioideae subfamily pf family Campanulaceae, containing many species, some of which are garden plants and "alyssum" is any of several plants, of the genus Alyssum, mostly of Eurasian origin, that have racemes of white or yellow flowers.