Thale Cress (Arabidopsis thaliana) is a plant from the Brassicaceae family, cousin of cabbages and mustards. It is small and slender.
It looks like nothing much, little white flowers four petals each on a thin stalk. The fruits, siliquas, are long and narrow. The plant is nearly without leaves, the basal rosette has disappeared when flowering began. But Thale Cress knows how to make seeds, however.
See here the results in good circumstances, in a field sowed with grass seed that did not germinate as it should. Instead of grass, enormous amounts of Thale Cress have emerged.
Thousands of little plants tremble with the breeze. It is very well possible next year will be completely different, there will be grass and millions of Thale Cress seeds will wait for another year.
But for now everything goes very well for Thale Cress.