what is this purple coloring?

[WayneByerly]

the aerole (and some surrounding areas) of one of my cacti (Ferocactus flavovirens) has turned purple this last winter to this spring. anybody got an idea? Ignore the cut spines. I needed to get to some black stuff at their base and it was easier to cut them close so i could brush/wash that black sludge out from between them.

20191025_095055.jpg (48.26 KiB) Viewed 830 times

thank you in advance for any opinions.

[anttisepp]

South mexican species, probably reaction to winter low temps. Next winter to the higher shelf.

[cactushobbyman]

I maybe wrong, but your plant looks like Ferocactus emoryi. I have my in the yard and the skin does turn purplish. My are located in direct sunlight all day. My younger plants are more protected from direct sunlight. I transplanted them to the yard after they were more than 6 inches in diameter.

[WayneByerly]

I maybe wrong, but your plant looks like Ferocactus emoryi.

i've got a F. emoryi AND a F. flavovirens. The F. emoryi has longer redder spines (at least they do when they get a little older). You can SEE what this one looks like... shorter, whiter spines.

I have NO idea how variable this genus is, so have NO idea how much that plays a part in your ID suspicion, but those are the ID's I have always had. I am VERY cognizant how mistaken growers CAN be. But then I may be wrong too!

It's POSSIBLE (though not likely) that their tags got switched, but I am fairly certain that these ID's are correct.

I have my in the yard and the skin does turn purplish. My are located in direct sunlight all day. My younger plants are more protected from direct sunlight. I transplanted them to the yard after they were more than 6 inches in diameter.

All of my Ferocactus are in the greenhouse, in direct sun. As most that live wild are. They are both in 6 in pots, and BOTH are 5+ years old and larger than a baseball. Closer to a softball actually. But not quite 6" across. Neither have ever flowered.

[WayneByerly]

South mexican species, probably reaction to winter low temps. Next winter to the higher shelf.

this spring it started to get warmer. I opened the greenhouse door for the day and forgot to close the door. the temps went down to freezing and I didn't catch it.

this happened TWICE!

so i guess (like i suspected) that this purple coloration is caused by temps going lower than this plants "minimum" temp. sigh.

thanks for your input.

[greenknight]

The black gunk was probably nectar from extrafloral nectaries that molded. If there aren't any ants to consume it, that's what happens.