Here are my navigator tree locations on different continents:

Lucentium:

The main tree is 20 north from Lorenchia central park.

413, 142 "lorenchia"   astacia, cattree, karatur, monk, swamp, vk
173, 443 "swamp"       monk, lorenchia
233, 151 "cattree"     lorenchia
391, 148 "monk"        lorenchia, swamp
296, 126 "astacia"     lorenchia
50, 250  "katatur"     lorenchia
57, 149  "vk"          lorenchia, startloc

Laenor:

The main tree is 5 south from the south cross (SC).

365, 480 "aresc"       mist, dbridge, fulgurite, newbiemtn, northrend, darkcastle, moonrind, eightleg
468, 572 "mist"        aresc, dbridge
280, 479 "newbiemtn"   aresc
713, 60  "northrend"   aresc
341, 578 "darkcastle"  aresc
571, 483 "moonrind"    aresc
634, 355 "fulgurite"   aresc, startloc
491, 496 "dbridge"     aresc, mist
221, 490 "eightleg"    aresc

Rothikgen:

The main tree is 2 north, 14 west, 7 north from the center of Shadowkeep.

217, 264 "sha"          peril, aldor, beast, taiga, icecastle, shack
320, 296 "peril"        sha, taiga
83, 112  "aldor"        sha
287, 60  "taiga"        sha
127, 169 "beast"        sha, peril, startloc
356, 269 "shack"        sha

Desolathya:

The main tree is 1 west, 3 northwest from Tiburcio.

300, 302 "tibu"         carnival, orac
203, 60  "carnival"     tibu
301, 94  "orac"         tibu

Furnachia:

The main tree is 4 south from Furnachia ferry.

190, 85  "rily"         twisted, perins
99, 205  "twisted"      rily
272, 171 "perins"       rily

No graphical map for Furnachia trees at the moment.

NOTE: Maps used from PupuMaps project with permission from Ggr.