  Most star complexes are in fact complexes of stars, clusters and gas clouds;
term "star complexes" was introduced as general one disregarding the
preferential content of a complex. Generally the high rate of star formation in
a complex is accompanied by the high number of bound clusters, including
massive ones, what was explained by the high gas pressure in such regions.
However, there are also complexes, where clusters seems to be more numerous in
relation to stars than in a common complex. The high rate of clusters - but not
isolated stars - formation seems to be typical for many isolated bursts of star
formation, but deficit of stars might be still explained by the observational
selection. The latter cannot, however, explain the complexes or the dwarf
galaxies, where the high formation rate of only stars is observed. The
possibility of the very fast dissolution of parental clusters just in such
regions should itself be explained. Some difference in the physical conditions
(turbulence parameters ?) within the initial gas supercloud might be a reason
for the high or low stars/clusters number ratio in a complex.
