Missouri Botanical Garden (USA) merged their plant name database with the World Checklist of Selected Plant Families (maintained by The Royal Botanic Gardens, Kew). This list was cross referenced with regional floras showing that ca 600,000 of names are synonyms. The new database, The Plant List, forms a working list for all known plant species. It provides the accepted Latin name for the species and links to the synonyms, it also lists unresolved plant names (known names which are not accepted nor synonyms.
The Plant List contains 620 plant families and more than 16,160 plant genera. This is a perfect tool to use when you are deciding for the ID-information for your illustration. Link to The Plant List is provided under the heading "useful links" on the right hand column in this blog.