It is the first country in the world to create such a database, the National Botanic Garden of Wales said.
Wales has about 75 percent of the flowering plants found in Britain, and the database contains 1,143 plants and conifers, officials said.
The Barcode Wales project has been led by Natasha de Vere, head of conservation and research from the National Botanic Garden in Carmarthenshire, the BBC reported Wednesday.
Barcodes are short DNA sequences allowing plants to be identified from pollen grains, seed pieces, or roots and wood.
"Wales is now in the unique position of being able to identify plant species from materials which in the past would have been incredibly difficult or impossible," de Vere said.
"Through the Barcode Wales project, we have created a powerful platform for a broad range of research from biodiversity conservation to human health."
In the next phase of a three-year project, non-native plants introduced by humans will have their DNA recorded, officials said.