It looks a lot like Night Blooming Cereus (also called Queen of the Night). It's a cactus that blooms around 9 or 10 p.m. and is fully open by midnight and usually closes at sun up. What's baffling is that it appears to be daylight in your picture and the bloom is still open...
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.