Re: how do you classify a venus fly trap

Your question can be answered here: http://plants.usda.gov/
For common name type in venus flytrap 

When you get to the venus flytrap page, click on the plant classification logo 
to find the following:

Kingdom  Plantae -- Plants 
 Subkingdom  Tracheobionta -- Vascular plants 
  Superdivision  Spermatophyta -- Seed plants 
   Division  Magnoliophyta -- Flowering plants 
    Class  Magnoliopsida -- Dicotyledons 
     Subclass  Dilleniidae 
      Order  Nepenthales 
       Family  Droseraceae -- Sundew family 
        Genus  Dionaea Ellis -- Venus flytrap  
         Species  Dionaea muscipula Ellis -- Venus flytrap  

Most botanists leave out Subkingdom, Superdivision, and Subclass. It is now 
standard to say phylum (plural phyla) instead of division. Phylum and class 
names can vary depending on the taxonomist. Many botanists use Anthophyta as 
the phylum name for flowering plants and the class Dicotyledonae for 
dicotyledons.  

A common mistake is calling Dionaea the genus and muscipula the species. The 
species is actually Dionaea muscipula. By itself, muscipula is called the 
specific epithet. Ellis is the name of the taxonomist who provided the genus 
and species names.

You can search on google.com for venus flytrap and find lots more info on this 
fascinating plant.