Minimum spanning tree of the MSP population is defined as T(218, 217), separated into significant branches according to the algorithm described in the text (see Sect. 3). The branches group a comparable number of pulsars: gray (39), orange (20), dark blue (31), brown (54), dark green (30), and pink (16). The trunk (in dark khaki) has only 14 nodes, with 14 others (in sky blue) that are not considered to pertain to any significant branch or trunk and appear to be the noise of the former structures.