Two flowering male catkins from a goat willow tree (Salix caprea). Original public domain image from Wikimedia Commons https://www.rawpixel.com/image/3339356/free-photo-image-botanical-bud-catkinsFree Image from public domain licenseOak (Quercus robur), hazel (Corylus avellana) and hornbeam (Carpinus betulus): fruiting and flowering twigs.… https://www.rawpixel.com/image/13965901/image-plant-tree-artFree Image from public domain licenseCommon beech (Fagus sylvatica) and Spanish chestnut (Castanea sativa): leafy and flowering twigs. Chromolithograph by W.… https://www.rawpixel.com/image/13963359/image-flower-plant-grassFree Image from public domain licenseThree plant stems with catkins, all from named types of willow (Salix species). Chromolithograph by W. Dickes & co., c. 1855. https://www.rawpixel.com/image/13952389/image-flower-plant-grassFree Image from public domain licenseFour plant stems with catkins, all from named types of willow (Salix species). Chromolithograph by W. Dickes & co., c. 1855. https://www.rawpixel.com/image/13952797/image-flowers-plant-grassFree Image from public domain licenseFour twigs with catkins, all from named types of poplar or aspen (Populus species). Chromolithograph by W. Dickes & co., c.… https://www.rawpixel.com/image/13967553/image-flower-plant-grassFree Image from public domain licensePng fuzzy willow branch, isolated object, transparent background https://www.rawpixel.com/image/10159050/png-tree-botanicalView licenseFour plant stems with catkins, all from named types of willow (Salix species). Chromolithograph by W. Dickes & co., c. 1855. https://www.rawpixel.com/image/13964238/image-flower-plant-grassFree Image from public domain licenseFour plant stems with catkins, all from named types of willow (Salix species). Chromolithograph by W. Dickes & co., c. 1855. https://www.rawpixel.com/image/13951233/image-flower-plant-grassFree Image from public domain licenseA willow (Salix violacea): leafy and flowering branches with floral segments. Coloured engraving, c. 1804, after H. Andrews. https://www.rawpixel.com/image/13955362/image-flower-plant-grassFree Image from public domain licenseFour plant stems with catkins, all from types of willow (Salix species). Chromolithograph by W. Dickes & co., c. 1855. https://www.rawpixel.com/image/13961113/image-flowers-plant-grassFree Image from public domain licenseFour plant stems with catkins, all from named types of willow (Salix species). Chromolithograph by W. Dickes & co., c. 1855. https://www.rawpixel.com/image/13954995/image-flower-plant-medicineFree Image from public domain licenseA plant of the Urticaceae family: flowering stem with pink, catkin-like inflorescences. Watercolour. https://www.rawpixel.com/image/13969846/image-plant-tree-artFree Image from public domain licenseFuzzy willow branch isolated object psd https://www.rawpixel.com/image/10159091/fuzzy-willow-branch-isolated-object-psdView licenseFour plant stems with catkins, all from named types of willow (Salix species). Chromolithograph by W. Dickes & co., c. 1855. https://www.rawpixel.com/image/13953325/image-flower-plant-grassFree Image from public domain licenseBirch (Betula species): twigs and catkins. Pen and pencil drawings. https://www.rawpixel.com/image/13970132/birch-betula-species-twigs-and-catkins-pen-and-pencil-drawingsFree Image from public domain licenseFuzzy willow branch, isolated design https://www.rawpixel.com/image/10115735/fuzzy-willow-branch-isolated-designView licenseHazel twig (Corylus avellana) with an associated insect and its anatomical segments. Coloured etching, c. 1831. https://www.rawpixel.com/image/13984546/image-cartoon-plants-artFree Image from public domain license