The evolution of plants had already started 475 million years ago. The ancestor was actually a freshwater green alga called charophyte, which at first evolved to
non-vascular plants (liverworts, hornworts and mosses) and then seedless vascular plants (ferns). It was not until 360 million years ago that seed plants, including non-flowering plants (gymnosperms) and flowering plants (angiosperms), emerged on Earth.

References:
1.
https://www.doterra.com/US/en/botany-living-organism-plant-evolution
2.
https://antranik.org/the-evolution-of-plants/