It's a Gardenweb error. Try opening a free Photobucket.com account, uploading pictures, then use the HTML line, copy and paste here. You can past multiple photos on any post, any reply post, etc.

Definitely a Mammillaria (a cactus), a genus that I don't know well. It reminds me of Mammillaria prolifera, but it is taller than mine was. Could be a starting point, at least.

Whitney My plant is just a little bigger than yours. I would dare to say that it is Austrocylindropuntia, most likely subulata. You can google photos of each species (about 10?-11? 12?) and compare. Color will vary a lot depending on light succulents get - so the color alone will not be sure way to correctly ID any plant. In low light, plants will also grow skinnier, longer/taller and often spindly stems. If they have leaves, they are usually too far apart. So the plant could look totally different than it should (I am not saying yours does). Even old/mature plant grown under not-so-suitable conditions will not look as it should.

Mine is definitely not RQ, but most likely a Echinopsis/Lobivia hybrid. Funny how the tag said Trixanthocereus. Um ok;)? My RQ and mystery cactus together. Very different. The mystery cactus has long and short golden spines, which I have never seen golden spines on RQ, and the flower is an orange red not fuchsia. It’s really bright in person. Plus the way the MC grows is different than RQ. RQ gets new growth from the base and up and down the sides of the old growth, the way C. sylvestrii grows. So far MC’s new growth comes only from the base of the plant, similar to how most of the growth starts on my Trichocereus grandiflores. RQ Mystery cactus Both cactus have been getting same strong sun and the longer RQ gets sun the more purple it gets, but the other turns more golden. Alain, when I first looked at E. hauscha I didn’t think much of it, but on a second look there are some pics that look really close to the my cactus. I wonder if there is hauscha blood in my cactus;). Tyler, thanks for putting up pics of your RQ because it just shows how different each one can look, and I don’t have that type of RQ. But you can see the differences between yours and the MC;). Dinie, good info;). Thanks everyone:)!