First flower on my domino cactus (echinopsis subdenudata)! :D

One of the fuzzy buds exploded into a several-inches-long spike yesterday; I checked on it a couple of times last night, but when it still hadn't opened a bit after midnight I thought I had another day... Checked on it at 7am, and found this. :) The bud on the left is the next one to watch - this time i'm not going to take any chances, if it looks like it might be thinking about opening I'm going to bring it indoors for the night and set my camera up for a time-lapse... :D