During a large part of the year you can find Least Pepperwort (Lepidium virginicum) in bloom. It makes a lot of tiny white flowers and if for one reason or another a branch is cut, it just begins anew to make new branches and flowers.
Often you see flowers, fruits and remnants of fruits on the same plant. The fruits are little disks with an incision on top.
At the first stage of flowering there are still many leaves, rather long and with some dents; with time it looses the larger part of its leaves and concentrates on flowers and fruits. How can it manage with so little chlorophyll-driven production of energy? It does not have a stock in its roots, it is an annual plant without a big root-system. Maybe it does not rely too much on extra energy, it produces as many seeds as long as possible until it is spent.
Here a well-developed plant. It has the upright shape typical for Lepidium Pepperworts. You can find Least Pepperwort mainly in antropogenic places, like here on a little-used driveway.