Should the opening supplication be recited if the worshiper joins the congregation in the second rakʿah, or has its time passed?

The opening supplication (Du'a al-Istiftah) is a Sunnah according to the majority of scholars. The congregant (ma'mum) should recite it unless he fears that the Imam will bow (ruku'), in which case he should limit himself to reciting Al-Fatiha. If the congregant enters while the Imam is standing, he should recite the opening supplication and Al-Fatiha, and then listen attentively to his Imam. However, if he enters while the Imam is in the bowing position, he should say "Allahu Akbar" and bow with him, and in this case, Al-Fatiha and the opening supplication are waived for him.