Yes, you can plant Plumeria seeds from any flower without pollination. Plumeria seeds, even if they have not been pollinated, can be collected from flowers and planted. However, seeds produced without pollination will be genetically identical to the parent plant (clones) rather than exhibiting the genetic variability that occurs through cross-pollination. Planting seeds from unpollinated flowers is a method of propagating Plumeria clones and can be used to propagate cultivars with desirable traits. For genetic diversity, it is recommended to collect seeds from flowers that have undergone cross-pollination.