Ref1
https://books.google.com.my/books?id=9__cYvDD94oC&pg=PA244&lpg=PA244&dq=yield+Poa+trivialis&source=bl&ots=1Ja0CQev2S&sig=ACfU3U0ESgb-4Hat0z_SRUSPdWrBz7Jklg&hl=en&sa=X&ved=2ahUKEwiNyMfTvfngAhXd73MBHYnICBUQ6AEwBXoECAQQAQ#v=onepage&q=yield%20Poa%20trivialis&f=false