Help with a cactus

[tabbylvr]

Hi, I'm new to this forum and I probably have the blackest thumb in the world. Sigh. I'm really looking for some help here. I "inherited" a couple of cacti 3 years ago and have to admit that I haven't given them much care at all. Just recently have I gotten into the gardening thing and although I plainly suck at it, I'm not willing to give up yet. I do have pictures to post as well which will probably make it a lot easier to help me. Anyway, I already know that the bigger cactus has to be repotted. I also know that it is malnourished. The people who lived in our house before us definitely didn't do anything for it and, like I said, I haven't until recently. About a month ago I started to water it regularly and bought some cactus food (drops to put in water). It seemed to have revived it some at least. I don't know what type of cactus it is either, so here's a picture:

and a close-up:
.

My main concern is the coloration of the center "leaves". Why are they yellow/brownish? I've been watering regularly and the new "leaves" are bright green. My second biggest concern are these spongy looking circles that look a whole lot like fungus to me:
.
I don't want to repot the plant if it has a disease (unless it can be fixed). Lastly, the cactus is flowering at the moment and has one yellow flower. The other 2 buds never developed but instead just kind of dried up:
.

Any help would be greatly appreciated.

[tumamoc]

That is some type of Opuntia species, commonly known as prickly pear. It's hard to tell much from the small pictures (but better than no pictures at all!), but I think the brown coloration around the trunk of the plant is normal. They turn woody at the base. In fact, large Opuntia resemble trees. If you can post bigger pics, we may be able to help you figure out what those "spongy looking circles" are.

[hegar]

I agree with tumamoc. I placed the image of the "spongy looking circles" on my desktop and magnified it. However, I cannot figure out, what the spots are. If they were somewhat elongate and soft, I would think, that those are mealybugs. If they are circular, they could be armored scale insects. Does anything you see listed under "Pests and Diseases" right under the CactiGuide.com CactiForum headline resemble what you do have?
You can go ahead and use tweezers or some other tool in order to find out, if these structures are soft or hard, and whether or not they detach from the stem piece or are anchored or embedded in it. It may just be dead callus tissue and there is nothing to worry about.

Harald

[tabbylvr]

Thank you for the replies. I will post better pictures and investigate with tweezers to be sure. I think it may be dead callus tissue...I've seen some other circles like that with spines (thorns?) sticking out of them. I'm still concerned with the color of the older pads - they are yellow with what looks like brown crusting on them while the newer pads are bright green. Does the plant need more water? Is it true that you can simply take a new pad and stick it in a new pot and it will grow? Maybe that's a good way to go since the plant seems to want to grow horizontally and the new pads get heavy and break off easily?

[hegar]

Yes, the easiest way to produce more prickly pear cacti is to just twist the "pad" or cut it off where the node is. Then I would place the separated pad on its side for a week or so, until a callus skin has formed. After that you can place it into cactus growing medium and most likely it will form roots and voila you have a new plant.

Harald

[bluetexasbonnie]

The pad will root by simply laying it on the ground flat. It will eventually draw roots from the center. This gives it a stronger, more stable base. This is how they regrow in the pasture.

They usually curl up into a cup shape and look pitiful for a long while - maybe as long as a year. Water as often as you water the other cactus, but do it either from the bottom or side. Though I have never seen it happen, I suspect that water sitting in the cup for very long would promote rot. If you live in a cooler clime than south Texas, a propagation mat to keep the soil warm would probably speed the process.