Why would you assume that?
These seeds were found on my expedition through the southern parts of Mexico. I was lucky enough to be offered about an ounce of purple buds while traveling deep in a Oaxaca sierra. Found a few seeds.
The plants that grew from those seeds are all purple and identical in structure. The nature of the location makes me believe this is a landrace.
I guess the credit would go to the town and its farmers.
Oh ok, thought it was the Purple Mexican by CBG which is Oaxaca 79' x PCK. But if you collect them by yourself it's very nice,sorry my fault.
Maybe it's time to pop some fem. Oaxaca IBL by Esko. bought a few packs month ago. They are also very purple looking on pictures like yours.