Oligocene - Flora

Flora

Angiosperms continued their expansion throughout the world as tropical and sub-tropical forests were replaced by temperate deciduous forests. Open plains and deserts became more common and grasses expanded from their water-bank habitat in the Eocene moving out into open tracts. However, even at the end of the period grass was not quite common enough for modern savannas.(Haines)

In North America, subtropical species dominated with cashews and lychee trees present, and temperate trees such as roses, beeches, and pines were common. The legumes spread, while sedges, bulrushes, and ferns continued their ascent.