This category should contain only articles about the subfamilies of plants, when the articles are at the scientific name, or redirects from the scientific name in the case of monotypic taxa or articles at the English name. The only subcategories should be those that contain such articles or redirects (e.g. "Category:subtaxon subfamilies"). It should not contain any other categories.
For guidance on categorizing articles on plant subfamilies by rank, see Wikipedia:WikiProject Plants/Categorization#Taxonomic rank categories.