The plants and seeds that you get at the beginning of the game are all common plants (Tier 1). You will never start the game with any hybrids, such as Fern or Grass, since you have to produce those from cross-pollinating different species plants.

The reason we have this thread is to let people know that the Citrus and Ball "flowers" and the Reptans and Cactus foliage cannot be produced by crossing other types of plants and flowers. You must either have the plants or seeds already, or you will need to buy the seeds for them or create those species by mutating other species.