Peanut (Arachis hypogaea)
The peanut is also known as the groundnut. The flowers are yellow and when they have finished flowering the plant presses the small pod down into the soil, where it continues to grow.
In northern countries one has to grow early varieties of peanuts, but these can be hard to find. The best is to precultivate the plants or grow them in pots. When growing in the ground you must have soil that is soft enough for the pods to be able to enter it.