I don't know what those ring-like features are, but I advise removing those leaves and throwing them in the trash. Josh

Hi there! Lets see...in actual fact I think you have already answered your own question without realising it!!! Those plants look as if they could do with a 'good square meal' and the fact that you are unsure about what they are potted in makes me think they have been in the same mix for some time maybe? Both those factors would stress any plant and could be the cause of the odd looking leaves...just my ideas ;) You also say one put out new leaves when moved to a brighter place proving they do not take well to low light conditions. They will happily grow in, and do prefer a fast draining mix, as anything with peat or water retaining soil could be problematic for them. I think it best if you do take a look 'down below' and see what the roots look like and get back to the forum if you need to. I personally would also cut them back and re-pot in a fresh fast draining mix as they respond rather well to a cut back ( I have just done 2 of my large ones and posted about them on here). Their thin drooping stems and sparse leaves indicate a lack of light, food and water. I hope they will do well for you so keep in touch and I'm sure the Jade experts will chime in with their suggestions soon, good luck. Gill UK

Wow, thanks for the responses already. I've done a little reading in the archives since posting my question. I purchased some potting mix labeled for cactus, but it seems that those in the know are potting Crassula species in DIY mixtures, the most referenced of which consists of pine bark fines, something called "Turface", and crushed granite. I assume this sort of mixture is therefore considered superior to packaged commercial products like I found? At this point, I have not chopped off what's left of the root ball (but there isn't much left, it's pretty much just a bare stump that was sitting in the dirt); it sounds as though the recommendation is to wash off all the old dirt, cut off everything that's mushy, let it dry/callous over for a few days, and then rest it in fresh soil, leaving it unwatered until there are signs of recovery? Curious though; why the cinnamon? Is it a natural anti-fungal or growth stimulant?

Oh me, oh my; I am so confused! :>) A hint that will help us help you -- when you post about a certain question, always continue on the original post. Right now, you have 3 going for the same topic. I posted what I think are the answers elsewhere, namely http://forums.gardenweb.com/forums/load/pests/msg0917423132724.html?2 Here is a link that might be useful: answers for you