Wednesday is yellow, and so is the centre of this cool flower.
In Venezuela it has various common names, but the two I've heard the most are 'Rabo de iguana' (meaning iguana's tail) and 'Pitahaya de bejuco' (which means something like 'dragon-fruit from a vine'). In the scientific word, this is a plant from the genus Hylocereus. I'm not sure of the species, sorry.
This flower stays in its bud-state for days before it begins to bloom one afternoon at dusk. It lasts only one night, as it begins to wither as sun rises again. During the night of the blooming, an amazing sweet smell surrounds the flower. A performance definitely worth the wait.
Taken in Caracas with a Canon EOS 40D