I got this little P. brevicaule a few weeks ago and planted it. It seems well rooted. I have not watered it since and the soil is dry. Should I water now or do I wait for new growth and such?
I have found this plant is real water sensitive. I would wait for new growth.
You might consider a very little water during its dormancy.
Here is the source of my information.
It looks like the soil is quite rich/heavy/almost all peat. I think I'd re-pot into something a little less peat-rich.
You can see the soil has pulled away from the sides of the pot, in the photo. I've heard that this can sometime be the reason for failure because the shrinking and expansion of the peat from the moist/dry cycles can/will break the fine/smaller roots and this can promote rot.
I think I would also re-pot the plant a little higher in the pot, for both improved air circulation as well as getting the plant up into the light better. I'm not sure how you grow this (under lights, outside, in a greenhouse, etc.), but I think it would benefit the plant to be higher in the pot.
Thanks tl3. That potting medium is something the seller sent along with the caudiciforms I bought. Thought I'd try it but not sure exactly what it is. It does drain well. I do think I will repot the plant higher as you suggest. It seems to be well rooted when given the "tug test". It grows inside on the dining room table in front of a south-facing window with a semi-sheer curtain to block the direct sun.