Statistical properties of the APOGEE strings (see also Table A.1). The blue histograms denote the normalized frequencies for the 25 APOGEE strings identified outside the Orion Nebula Cluster with positions l ≥ 209.3 deg or l ≤ 208.7 deg. From left to right and from top to bottom: a) number of sources per string; b) fraction of young APOGEE objects (i.e., with Spitzer and/or XMM counterparts) per string; c) total length; d) mean distance to the nearest member of the string; e) maximum velocity difference within a string; f) internal velocity dispersion per string. The vertical red dashed lines indicate the mean value in each of the above distributions.