I have seen seed from various sources which have UG field numbers. Does anyone know who this collector is, and if there is a list of these numbers available?

Hey Chris,
UG stands for Ulises Guzmán. I think a Mexican Field-researcher .
Whether he has a field-list, escapes my knowledge.

I only know the UG 1370 = M. aff. multihamata from Cerro de la Vibora, Mich.
may be the same as TL 868.
__________

Holger

Thanks Holger.
The UG numbers that I knew about was 1370 and I'd seen reference to some others. I see that he has published quite a number of articles, from a quick Google search, so maybe I will try to make contact.
Best wishes,
Chris

Hi Chris,
On Mammillarias.net there are some Fieldnrs under Guzm?n Cruz L. U.
I guess that's your man.
Paul