Euphorbia PBI subgeneric classification
For any of the curators who have been working on Euphorbia, Euphorbia PBI has a data portal where essentially all the species have been assigned subgeneric classification (under description). I've been working through the majority of the species as I find them and should have gotten all the North American species that have been added so far and have been slowly working through others. All this to say, there is a single source where the information can be referenced if you are interested.
Here's the link: http://app.tolkin.org/projects/72/taxa
