Well I think Noah would have had to have brought most of land vegetation onto the ark because they wouldnt survive being underwater for too long. There are many species of plant that will be too badly damaged after being submersed in H2O for extended period of time. Or maybe he just collected the seeds? That would have saved a lot of space.
Seeds can float, and be carried by currents.
Obviously vegetation had begun to re-grow before the ark was opened.
What plants growing at that time would or would not survive isn’t known but seeds? Perhaps, but as I note, the Bible is just silent on that. Since Noah became a farmer with a vineyard after coming out maybe uneaten grain or perhaps vines survived the waters? The Bible just doesn’t say.