Basing on the latest results of the PNPI (Gatchina) and QM&W College (London) groups, I discuss systematics of theIJPCqq¯states in terms of trajectories on the (n,M2) plane, wherenis the radial quantum number andMis its mass. In the scalar sector, which is the most interesting because of the presence of extra states with respect to theqq¯systematics, I discuss: 1) the results of theK‐matrix analysis of the spectra &pgr;&pgr;, &pgr;&pgr;&pgr;&pgr;,KK¯, &eegr;&eegr;, &eegr;&eegr;′, &pgr;&eegr; and characteristics of the resonances in the scalar sector, 2)qq¯‐nonet classification of scalar bare states, 3) accumulation of widths of theqq¯states by the glueball due to the overlapping off0‐resonances at 1200–1700 MeV, 4) systematics of scalarqq¯states, both bare states and resonances, on the (n,M2)‐plots, 5) constraints on the quark‐gluonium content of the resonancesf0(980),f0(1300),f0(1500),f0(1750), and the broad statef0(1420−70+150)from hadronic decays, 6) radiative decays of theP‐waveqq¯‐resonances: scalarsf0(980),a0(980), and tensor mesonsa2(1320),f2(1270),f2(1525). The analysis proves that in the scalar sector we face two exotic mesons: the light &sgr;‐meson,f0(450), and the broad statef0(1420−70+150), which is the descendant of the glueball. © 2002 American Institute of Physics