CactiGuide.com

What Blue Cactus am I?. I have spent a long time on Llifle looking through everything

Echinocactus platyacanthus? Probably wrong, but I took a shot.

Thanks Spence.. Looks spot on

Agreed. Quite Blue this one!

I think its wild that it turns into this..

Indeed.
It is amazing to see how many ribs it has to add to reach full size. Smaller species have a higher number of ribs since they are young. The bigger the species, the number of ribs will be smaller when young (right? thats something my little platyacanthus made me think, not sure it is correct).

This group is among my favorites. They need much space for roots, much sun and regular watering in summer, fertilizers also suit fine. Fast grower in optimal conditions.

Thanks guys for the help..
Mike M

Hi Mike,

not sure but. . . Ferocactus emoryi


K.W.

K.W. wrote: ↑Sun Aug 07, 2022 3:52 pm Hi Mike,

not sure but. . . Ferocactus emoryi


K.W.

No way 'Jose'

K.W. wrote: ↑Sun Aug 07, 2022 3:52 pm Hi Mike,

not sure but. . . Ferocactus emoryi


K.W.

I am just a novice, but when I looked up K.W's suggested ID on cactiguide.com the first photo seems to closely resemble Mike's photo, except that it is not blue. Any chance the cactiguide photo is a mis-identification?

anttisepp wrote: ↑Fri Jul 29, 2022 10:20 pm This group is among my favorites. They need much space for roots, much sun and regular watering in summer, fertilizers also suit fine. Fast grower in optimal conditions.

And quite hardy, from experience. I have about 15 to 20 plants of Echinocactus platyacanthus / E. visnaga (what is the difference, by the way?), sown somewhere 20 years ago. They are grown hard, and still just 8 centimeters in size. But they have survived the last few years in an unheated greenhouse in the winter. This includes the one with the severe cold of february 2021 when it got around -15C for a few nights. I have lost just one plant, but that could have any reason.

If you look up on Llifle the pictures do match. Echinocactus platyacanthus.

Agreed it's E. platyacanthus.
They can be quite blue when young, had seen them in a friend's nursery.
Here is the picture for young E. platyacanthus (on the left) and F. emoryi.
Can see the different colours of the spines.