Willow (Salix spp.)
Flowering: March - May
The tree may reach up 20 to 25 meters height. The alternate leaves are entire or serrate. Willows are dioecious, meaning that male and female catkins grow on separate plants. The catkins are erect and cylindric or ovoid. Male plants may be recognized by their yellow color, which is due to the stamens of the catkins.
The willow species are adapted to bright exposure and humidity. They are frequently found along river banks, in meadows and flooded forests.
The willow pollination is mainly mediated by insects but also by the wind. Allergy to willow pollen is not frequent. The willow branches used in flower arrangements may cause allergy events to sensitized individuals in enclosed spaces.