u/Every_Association45

Image 1: It looks like one of the smaller globules rotted in contact with soil and transmitted the rot to the one at the top. The top one is firm, even at the blackened part, and the globule itself won't come off easily from the rest of the plant (it's firmly connected).

Image2: Side view of the same globule, showing lateral expansion of the darkened tissue.

Image3: Another globule, perhaps with a different sort of problem.

General conditions:

This puna was recently acquired (May 2026) and is in a mix of sand, pumice, and cactus soil. Usually, I add more pumice to the top layer to prevent water contact, but I obviously missed doing so here.

The cactus is on the south-facing windowsill, gets lots of sun and breeze, and I soak it every 2-3 weeks.

Looking for:

• Suggestions on what both issues might be
• Proper course of action to stop the spread to the rest of the cacti

Thank you very much!

Ferocactus emoryi subs. rectispinus

Added some photos with blank A4 paper for a better view of the ratio. Since it started getting a ton of sun and heat (thank you, summer), the spines are going extra wild :D

Just showing my Thelo off. Makes me love mornings, as it's the first thing I see when I pull up the shades! :D

EDIT: I see there's some confusion as some mention Thelo and others Fero, so here we go...

Thelocactus rinconensis var. lophothele is the one in the front with big off-white spines. I agree, a mouthful within a mouthful.

Ferocactus stainesii (aka. pilosus) is the one with reddish spines in the background.

Both make me happy :D

Location: Zadar area, Croatian coast, beachside, lots of direct harsh sun with some shade throughout the day, and plenty of salt spray.

Soil: 10-15cm layer of coarse gravel (construction addition) and rock with marine fossils (naturally found on the beachside) on top of red-clay-dominant soil.

Date: 1st week of June 2026.

Help me figure out what this is! Thank you! <3 :D