---
title: "Does anyone know what this stuff is on the intersections of the…"
description: "Does anyone know what this stuff is on the intersections of the stems? I don’t know if it’s a fungi. It’s mostly a hard substance, but I can kind of put my…"
url: "https://getplanta.com/community/lKxUkhzRR_aIJD7o1QvtwQ/DH4dbvWhj0hNwmYx3fuh8J"
community: "Pests, diseases and problems"
author: "Kirsten"
published: "2026-06-27T15:49:27.026511Z"
language: "en"
image: "https://images.getplanta.com/v1/resize/fNNEhrbV2gUvuwbi2sRUYVFufs3BoKT0bbvkFqjcSSc/kNd5K182TDGNHqitPO5H1g.webp?size=large"
---

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# Does anyone know what this stuff is on the intersections of the…

_Posted by Kirsten on 2026-06-27_

Does anyone know what this stuff is on the intersections of the stems? I don’t know if it’s a fungi. It’s mostly a hard substance, but I can kind of put my nail into it. The plant doesn’t seem like it has pests, but I feel like it’s been dropping a lot of leaves and maybe the stems attached to this substance seem to be shriveling? I got this plant from my aunt about 2 years ago, so not sure when it was repotted. I was thinking of doing it today, but want to know what this is first. I haven’t noticed anything unusual but my gut says I don’t think this should be here. Should I be concerned? The leaves and flowers that dry up and fall off seem to be normal

Update: Planta doctor says it’s corking (and a bit overwatered). I don’t know anything about corking, but it says that’s fine. Is that correct?

![Attachment 1 of 4](https://images.getplanta.com/v1/resize/fNNEhrbV2gUvuwbi2sRUYVFufs3BoKT0bbvkFqjcSSc/kNd5K182TDGNHqitPO5H1g.webp?size=large)

![Attachment 2 of 4](https://images.getplanta.com/v1/resize/fNNEhrbV2gUvuwbi2sRUYVFufs3BoKT0bbvkFqjcSSc/Ui0op0F8QnWdqMjoBQYA9g.webp?size=large)

![Attachment 3 of 4](https://images.getplanta.com/v1/resize/fNNEhrbV2gUvuwbi2sRUYVFufs3BoKT0bbvkFqjcSSc/p9jCajw_S5yIdaA2NA7P5Q.webp?size=large)

![Attachment 4 of 4](https://images.getplanta.com/v1/resize/fNNEhrbV2gUvuwbi2sRUYVFufs3BoKT0bbvkFqjcSSc/0UlUVXNeTlaFdh4iA8AZcA.webp?size=large)

## 3 comments

### plantgeek commented on 2026-06-27

this is absolutely a severe fungal infection, but i have no idea what fungus that is. there's an expert on here somewhere, i hope she finds this and can help you identify it, because i can't. general protocol for fungus on cacti is remove all of the visible fungus mass on the plant, spray down with rubbing alcohol, and greatly increase airflow with a fan or a windier spot. invest in a chemical fungicide, ideally a copper based one, as copper based fungicides can kill a pretty large range of fungi and spores.

#### plantgeek replied on 2026-06-27

also very important, completely isolate this cactus. move it at least three feet away from any other plants until you're absolutely sure you've killed the infection

### Whit\_Y commented on 2026-06-27

I disagree with the corking diagnosis and agree with plantgeek that this is a fungal infection.

Absolutely isolate from your other plants and remove all the visibly damaged growth. I would also recommend to check the root health for rot. If the roots look ok you could probably do a full chop to remove any remaining signs of fungal infection and then repot into fresh soil

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