The flowers on this Parodia rutilans are four days old in this photo, which is really old in the world of cactus flowers. The flowers are now seven days old, and have started to wilt a bit. Tomorrow, they will close for good and go to seed.
Many cactus flowers have a waxy look, but the P. rutilans flowers have the look of straw flowers. Perhaps that is why they last so long. For more information on the cactus see this previous post.