The Palm version and the Windows/Mac versions are different, and the species structure and breeding have been reworked. There are also 6 Magic Plants, not 4.

The species you mentioned are special rare ones that are not necessary to find all of the Magic Plants and are intended to be an optional end-game quest. Those plants (known as Tier 4 plants) can be discovered only by purchasing extinct seeds from the Supply Shop or by use of Mutation Liquid. None of the Magic Plants requires those species in order to be discovered.

You had mentioned previously that you needed the Aureus Scandens. To get the Aureus flower, you should cross a Venomous and Fourpetal or Citrus and Fragrant. To get a Scandens, you can cross Grass and Reptans. You might also find the explanation by sfrose in this post very helpful for understanding the breeding charts.