Calling them "wild greens'' is basically meaningless, the closest fish to that name is not a wild fish at all, but the tank bred, mixed heritage "green severums" that have been in the hobby forever.
I'll let ryansmith83 confirm what they are if he finds this thread, since he's had Heros severus and I haven't yet, but they do have the dark edges on the pelvic fins (and to some degree on the anal fin) and some have the half 7th bar, all typical of the Heros severus I've seen, which is the correct taxonomic name for what some used to call "sp. Curare," an outdated name now that they've been formally described-- same as what some call red tiger.