The objective uncertainty of the “species” classification category in vascular plants, which is caused by the absence of clearly defined thresholds in trait divergence between populations and the continuity of evolution, makes it possible for plant taxonomists to arbitrarily divide populations into “species.” In many researchers’ minds, the ideas about the special (sacred) meaning of the species category and the objective existence of species are still alive. All this negatively impacts both the understanding of the processes of biodiversity formation and the use of the species category in other areas of fundamental science and in applied research. The authors consider that the simplicity of identification and the convenience of use should be the most important criteria for species segregation. According to our expert estimates, at least 80% of florists and taxonomists in the world use this criteria, maybe sometimes unconsciously. The possibility and applicability of other criteria, including reproductive isolation and age of taxa, are discussed.
Onipchenko et al. (Sun,) studied this question.