Macro areoles turn black when wet

[OPP]

I have two macro tips, both rooted well, but when any water touches the areoles they turn black.

All my other cactii, all planted in the same soil mix, do not do this.

Is this something that only happens to macros or am I doing something wrong?

I have stopped watering them thinking that it was due to overwatering but even a tiny amnount of water turns the areoles instantly black.

Anyone elso come across this problem?

[Foo]

Not sure if its a problem. Actually i doubt that it is, ive seen something similar with other sp.

[tipz]

if it is the tipz macro ( which it is if I remember correctly, it is normal for that plant )

[M S Smith]

Not sure I see the problem. Sounds like a simple case of brown felt looking black when wet.

~Michael~

[theuserformallyknownasd00d]

Yep, my Tipz mac does this, as do a few Peru hybrids