Agreed, Ferocactus acanthodes occurs northwest completely to the Utah border and beyond. I found at least a dozen range maps in need of adjustment. I love this book!!!
Dean

Which ones??? I saw a few range maps that need to be "tweaked" as well.
All in all, this is the best book of its kind that I've ever seen.
Dean

Dave, this whole group of Mammillaria is full of problems. Far to many photos of them around with names that are just a "best guess". Much more needs to be done on site with these populations and until then the full range of variation and species boundaries will remain in question. I think...

All of those are possible explanations for the spine morphology presented in Steve's plant. Problems not answered are: No one know whether M. cruciger and M. huitzilopochtli will produce hybrids, especially natural ones, although it is likely that they will if they come in contact. The plant in ques...

I wouldn't pay too much attention to the "Words of Wisdom" you found; it is true that hybrids abound in Opuntia but they can be identified to species by morphology, locality, and chromosome counts. I'm working on Opuntia taxonomy in Utah and I live only 30 miles from Bryce Canyon. I've see...

Where in Utah did you find it. The plant is not Opuntia fragilis but could be an O. fragilis x O. polyacantha hybrid. Such hybrids are common in the state. As it grows and gets more of an adult look to it identification will be easier. The spines at this point look like O. polyacantha x O. fragilis ...

Thanks, that description settles the matter. The plant above in question is certainly M. crucigera and not M. huitzilopochtli.
Dean

I believe that your plant is M. crucigera but not all the populations presently included as varieties or subspecies of M. crucigera will be maintained in that position for very long. Still lots of work to be done with that group but it certainly contains some hybrid populations and possibly another ...

Baxter's seedlings look like good Hylocereus seedlings although etiolated as mentioned above. It is interesting how much they look like Opuntia seedlings.
Dean

Thanks Dave. If the Mammilarias.net photos of M. huitzilopochtli and description are accurate then I'd have to say that the plant above, in question, is not M. huitzilopochtli. Having 6 short, brown centrals vs a single elongated, black central is just too much of a difference to be the same species...

The plant above doesn't have the single enlarged central spine that is present in the examples given above for this species. 7george is right, there are about 20 radials and 5 to 6 short, brown central spines, none of which is enlarged as is often seen in plants labeled M. Huitzilopochtli. It does a...

Dave, thanks for the help but even after living in southern Mexico for a year doing research, I still can't pronounce the name the way the "locals" did. I agree about Aztec names. Very nice plant even if I can't pronounce its name.
Dean

The book is a great achievement, I wish I could attend. One of our group, Dorde Woodruff, will likely be there. Can't wait to get my copy!!!
Dean

Great to see that Jon Rebman has finally published some of the Cylindropuntia research he has been working on for years. Great job. Also, I can now openly refer to my plant of the Baja species Opuntia clarkiorum by name now that it is published. This Opuntia is NOT winter hardy in my area.
Dean

I guess there is always a remote possibility but it is likely very difficult, if not impossible) to cross Cylindropuntia with Opuntia. The two groups are actually not as closely related at past taxonomic arrangements suggested. While no direct genetic evidence appears to be available from chromosoma...