Thank you very much for your nice comments. That Thelocactus heterochromus did keep me waiting for a long time.
Here are two more images of yet another cactus that did refuse to bloom ever since our club salvaged it from the wild. I do have three Coryphantha macromeris plants and was almost shocked, when I noticed two flower buds on one of them. My last photos date back to 2008, when I planted the cacti under my "Chitalpa" tree, a hybrid of the Desert Willow (Chilopsis linearis) and Catalpa sp..
I had been told, that this plant needs shade in order to survive.
Well, perhaps it had too much shade. Now my Chitalpa tree is dying and because of the reduced foliage the cacti receive more sun. Perhaps that is also the reason why the Thelocactus heterochromus flowered once again.
Well, here are the two images I took shortly after noon this day.