Opuntia ID please - macrocentra?

[Paul in Essex]

Slightly off my radar but I think this might be macrocentra? No pic of flowers, sadly.

Muchas gracias

[TomInTucson]

Slightly off my radar but I think this might be macrocentra? No pic of flowers, sadly.

Muchas gracias

IMG_20231017_105129.jpg

Although I continue to aspire to be an expert on this genus, at this point I can only rely on my anecdotal experiences. Years ago (before there was very much concern from the Mexican government), I collected a pad of a colorful prickly pear that formed a (4-6') small treelike (with a short trunk) shrub. At the time I assumed it was the distinctive Opuntia gosseliniana. Over the years It persisted, and refused to die. I ended up with more than I would ever need, but the it's attractive nature kept me from discarding it. When I moved from California to Arizona, I left these content plants behind (you can't always keep everything when you relocate your collection). When I run across it again, I'll be sure to grow it acquire it. Here's a link to what is now sometimes called Opuntia chlorotica gosseliniana in AZ: https://www.opuntiads.com/wp-content/ga ... rnahan.jpg

[Paul in Essex]

Thank you Tom. That is an incredible resource! I only know a little bit about opuntias and it seems what I thought I knew is wrong!

[TomInTucson]

Thank you Tom. That is an incredible resource! I only know a little bit about opuntias and it seems what I thought I knew is wrong!

Ever since I found this site, I often used it to ID prickly pears. There's other good info.. there, but they clearly have a penchant for this type of cactus from this huge section of the cactus family. If you spend a little time there you'll discover that it's heavily influenced by David Ferguson (DJF). His opinions lean a little left of center, but I tend to agree with him. When it comes to his opinion on the relationships of the species of Mammillaria, I most whole heartily agree with him.

[Paul in Essex]

I have a book he co-wrote with Cheryl W Green called 'Prickly Pears' but I find the layout a bit confusing. The website is a lot clearer.

Back in the infancy of the internet there was a email group called 'Too Cold For Cactus' and DJF was a regular conbtributor. I always looked forward to his comments as he seemed to cut straight to the point well. I used to print off all the discussions, back then. I remember him saying, of Dasylirions, 'There are green ones with teeth, blue ones with teeth and green ones without teeth. Grow one of each and you've just about got Dasylirions covered'. Made me laugh. Of course he then went to to describe the differences and the way the populations intergraded, which was fascinating stuff. I wonder if there are people spending that amount of time in the field these days?

[RayW]

Yes Opuntiads.com is a great site, some years ago they split it up into 2 or 3 sites Chollas.com etc.
I remember seeing Dave Ferguson on a cable TV channel back in the day ( most likely a PBS channel ) walking round a meadow with cows in it showing a TV guy all the cacti growing there ( small Opuntias and Echinocereus etc. ).
Back to your ID Paul. there are 3 species which look very similar, macrocentra, gosseliniana and santa-rita. Looking at the size of the pads and the white or light coloured spines at the top of the pads I think Tom is spot on with O. gosseliniana.
The other 2 species have dark red spines at the top of the pads and different sized pads, I grow all 3 species and find them to be hardy in the British winter if kept dry. The Pads can go dark red with cold stress but soon colour up again in spring.
Is this plant growing in your garden rockery Paul ?

[Paul in Essex]

Thanks Ray.
Yes - just. I planted it this year, one of a few old plants I re-homed earlier in the season. Its in the 'new bit' so planted in rubble.

[TomInTucson]

I have a book he co-wrote with Cheryl W Green called 'Prickly Pears' but I find the layout a bit confusing. The website is a lot clearer.

I wonder if there are people spending that amount of time in the field these days?

I'll have to try and find that book, despite the possible confusion that might ensue.

AFAIK, the only people doing any interesting field work are the many amateurs (who mainly live near their habitat) on iNaturalist, and the ever energetic Czech explorers.

[RayW]

Spot on Paul, it will like rubble