We present the results of a study aimed at assessing the differences in the distribution of rotation speeds N(vsini) among young (1-15Myr) B stars spanning a range of masses 6M_{sun}<M<12M{sun} and located in different environments: seven low-density ({rho}>1M{sun}_/pc^3^) ensembles that will survive as rich, bound stellar clusters for ages well in excess of 10^8^yr.
Cone search capability for table J/AJ/133/1092/table1 (Stellar Data)
Cone search capability for table J/AJ/133/1092/table2 (Data for Stellar Associations)