The Angiospermae are the main plants in the world. They reflect the evolution of humankind, giving us a humananitarian aspect. The Gymnospermae were abundant in the time of the Reptiles and the Dinosaurs. The Angiospermae became domineering in the time after the dinosaurs, in the time of the birds and mammals. The mammals and birds are the warm blooded animals. This reflects the extra warmth they have for their offspring, the extra care and in the case of mammals the giving of milk.
The Gold series effect of the Angiospermae is subtle to see as it so pervading. It makes persons less hard, as survival is not the only issue anymore.
For practical purposes in homeopathy it is best to consider in principle the Angiospermae first. Only when the problem is very basic, in a way primitive, it is indicated to look as the earlier Phyla.