Populus nigra

Tree that grows up to 30 m tall. It has a slender trunk and crown that is sometimes very narrow (columnar). The leaves are simple, deciduous, alternate (this character is seen best in the middle of the branches, as at the ends they sometimes appear very close together), diamond-shaped or triangular, and finely serrated on the margin. They are bright green on the upper side and have a long stalk that appears flattened. The male and female flowers grow on different trees (dioecious species), grouped into elongated, hanging catkins. The female blooms are a discrete green, while the male blossoms are vivid orange colours. In October, the fruit capsules ripen and the two parts, or valves, open releasing numerous tiny seeds enveloped in cottony filaments that help their dispersal by the wind. This fluff is often confused with pollen, since its appearance coincides with the spring allergy season.