Even more recent than flowering plants: Grass.

> Before 2005, fossil findings indicated that grasses evolved around 55 million years ago. Finds of grass-like phytoliths in Cretaceous dinosaur coprolites from the latest Cretaceous (Maastrichtian) aged Lameta Formation of India have pushed this date back to 66 million years ago.

https://en.wikipedia.org/wiki/Poaceae

For reference, dinosaurs went extinct 65 million years ago.

Flowers are relative newcomers. This is because it required a relatively tight relationship between insects and plants. Coordination between species is trickier to evolve.