How is autochthonous flora different from resident flora and allochthonous flora from transient flora? They appear to be the same to me. Autochthonous flora is the indigenous flora of a microenviornment able to utilise the enviornment and colonise .i.e resident of the microbiota. Allochthonous flora is the non-indegenous flora that inhabits a microenviornment but unable to adapt or compete is removed after sometime .i.e transient. I would really appreciate answers with reference to authentic sources.