Aerial roots on a echinopsis Lageniformis

[mikethecactusguy]

When I received 2 of these they were both a bit dehydrated. When I potted both up I watered them once and let them sit a week. During that week this one popped a few aerial. So I gave them both a good watering and followed up a few day later with another since the soil dried out immediately. They both started to fill in after about a week. The roots stopped growing. That was a month ago. I've been watering everything in the greenhouse regularly. I was surprised to find all this new growth a few days ago on this one plant.
I know it's that plants way to find water. The humidity at night has been in the 40% region, but down to 10% during the day. Is the higher humidity playing with its moisture needs? Is it just looking for additional water?

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These 2 roots have actually grown into the soil. So they are active.

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Any thoughts?
Thanks
Mike M

[Shane]

Aerial roots on columnar Echinopsis species near the bases of branches seem to be common. I'm not quite sure why, but I don't think your cactus is doing anything unusual I think that's just what they do. My theory is that a hormone that encourages root growth is produced in the apical meristem and moves down the stem via gravity. I think some of it gets trapped in the low part at the bottom of the branch (much like water in a p trap under a sink). This would help basally branched plants develop their root system

[mikethecactusguy]

Thanks Shane.