1) Biologist 2) Classification expert 3) Classifier of living things 4) Life scientist 5) Systematist 6) Taxonomer 1) Divider 2) Systematist 3) Taxonomer 
• (n.) One skilled in taxonomy.
a scientist who studies the biological classification (taxonomy) of organisms and identifies species.
Tax·on'o·mist (tăks*ŏn'o*mĭst) noun One skilled in taxonomy. 
[n] - a biologist who specializes in the classification of organisms into groups on the basis of their structure and origin and behavior
taxonomer noun a biologist who specializes in the classification of organisms into groups on the basis of their structure and origin and behavior
A scientist whose job it is to classify plants, or other organisms, into their correct Scientific classifications. We use Genus and Species on this site. With new information available via DNA information there is currently a fair amount of reclassification happening.