The group is named after a principal member species, Streptococcus anginosus.

[1] They have been implicated as etiologic agents in a variety of serious purulent infections, but because of their heterogeneous characteristics, these organisms may be unrecognized or misidentified by clinical laboratorians.

[2] The unique characteristic of them from other pathogenic streptococci, such as S. pyogenes and S. agalactiae, is their ability to cause abscesses.

[3][4] Members include:[2] These nonhemolytic viridans streptococci were first described by Guthof in 1956 after he isolated them from dental abscesses.

[5][6] The organisms were subsequently recognized as normal flora of the human oral cavity and gastrointestinal tract with the ability to cause abscesses and systemic infections.