Most dicots have flowers with 3 or 5 petals, but this tree species has flowers with only 4 pinkish-white petals and 3 brownish sepals. The slightly longer and darker pink pistil remains after the flower is pollinated and the petals are shed. At the same time, the bilaterally symmetrical sepals curved inwards towards each other.
The ovary develops into a guava-like fruit with the rudimentary sepals looking like the fruit's nipple. The fragrant flowers are generally thought to be pollinated by bats or moths. Two links are attached below for reference: