Question

which criteria is used to classification of plants

Answer 1

Not physical structures. If that were the case, just about every Human would be ranked in a different genus or even species from one another do to size, skin, habitat, and other physical qualities, when really, we all have the same anatomy, and fundamental biological attributes.

Biological Classification
-Life
-Domain
-Kingdom
-Phylum
-Class
-Order
-Family
-Genus
-Species