The Triassic period starts 248 million years ago and continues to 206 million years ago. The super continent Pangea straddles the planet from pole to pole. The biggest extinction to occur has just finished wiping the planet clean of most life. The volcanoes are settling down but it’s still a harsh planet.
Ferns are still flourishing, smaller trees still are with us. The air is much drier especially inland. Because the continent reaches from pole to pole there is much diversity in climate and this shows in the plants of the period. We have cycads, ginkgoes, tree ferns, horse tails and ground ferns.
Bennettitales appear now but won’t last through the next period. They are cycad like plants the only real difference is a tendency toward branching.
Seed bearing plants are now exposing their seeds to the world and letting the wind do the pollinating. There is some evidence that the earliest flowering plants appeared during this period 220 million years ago. We have some fossils of a plant with a single leaf and two flowers. Veins in plant leaves are still asymmetric.
Dinosaurs emerge and expand through out the land many of whom are plant eaters. The planet warms and the climate becomes friendlier for life. Insects continue to expand, though smaller than they were previously. Small mammals are with us.
New fossils push the origin of flowering plants back by 100 million years to the early triassic
Flowering plants may be older than previously thought
First flowers emerge from Triassic mud
NYT Where did all the Flowers Come From?
Pollination in the pre-flower era