Night-blooming cactus

The huge, beautiful flower of the night-blooming Cereus cactus. Seen on my hike today to Tantalus Peak above Honolulu CBD, but I couldn't get the angle I liked to simplify the background. Rather than waste time right at the start of the hike I thought I'd have another go on the way back. 
Little did I know that between 9am and 1pm, the flower would wilt to a very sad looking version of it's early morning form. 
A good hike, lots of birdlife and some nice dense, jungle-like forest. Enjoyed it immensely, despite some mud and bitey bugs.