Simplify the following text for a Grade 13 native English-speaking person.
Original: However , by looking at the history of polyploidy in plant families , he argued that polyploidy was only common in herbaceous perennials and infrequent in woody plants and annuals .
Simplified: By looking at the history of polyploidy in plant families , he argued that polyploidy was only common in herbaceous perennials , but infrequent in woody plants and annuals .