Those branches are somewhat ridged, if you remove the bark you can see that the wood is striated. This is typical for the Grey Willow (Salix atrocinerea). Often it is difficult to distinguish the different Willow species, still more so because they easily form hybrids. In Dordogne, Grey Willow is the commonest species.
This big bush or small tree grows nearly everywhere in places where it is wet enough during a large part of the year.
Here an old specimen on the edge of a pond. It has finished flowering before the new leaves appear, and now the male catkins that lost their pollen have fallen and now float on the water surface.
The Salicaceae (Willow and Poplar family) are all dioeciousc. This means they have flowers with only pistils or only stamens, never both of them, and on every individual plant you find only pistillate or only staminate flowers, never both of them.
The catkins are downy, maybe that's why they are called 'catkins', But when they are in full bloom you don't see the downy hairs, the long filaments of the stamens topped with yellow pollen are longer than the hairs. In every catkin there are dozens of flowers, each with two stamens.
