citizen, page-7

Trees,
"what about human or earthling??"

Not too sure what you are getting at there Trees,Human or Earthling are just as inclusive as Mankind mentioned by K.
Actually I think Jerome1's use of Citizen is more apt as it implies a degree of growth not necessarily included in the other terms.
The point made by K and was one of inclusion as against division and separation.

The Quote was probably from a time when gender issues were
not as considered as now hence MANkind.

What about the broader sentiment of the quote trees?,I assume that was the point Jerome intended to make.One with which I heartily endorse as a Citizen of The World.