What flower or plant is this one?
I am not familiar with this plant, and haven't been able to find a definite identification of it, but I believe it may be some type of Metrosideros. The actual flower would have been fluffy looking, and what we are seeing is the calyx and single pistil left behind after the many long stamens have fallen.
I suggest taking it to a local nursery or university with a botany department for a better identification.
Thank you for your time... There is a some pictures additional... By the text you white... There is not stamens fallen... Is the only one... I've been browsing to send to someone that's knows but I don't find it in Brazil.
This looks like it could be in the Apocynaceae family (same family as the Plumeria) but I'll need more time to confirm. Does it exude a white latex when the leaves or stems are injured?