Birch bark Birch bark Birch bark or birchbark is the bark of several Eurasian and North American birch trees of the genus "Betula". The strong and water-resistant cardboard-like bark can be easily cut, bent, and sewn, which has made it a valuable building, crafting, and writing material, since pre-historic times. Even today, birch bark remains a popular type of wood for various handicrafts and arts. Birch bark also contains substances of medicinal and chemical interest. Some of those products (such as betulin) also have fungicidal properties that help preserve bark artifacts, as well as food preserved in bark containers. Removing birch bark
Pterocarya fraxinifolia appear in April, the male catkins thick and green, 7.5 – 12.5 cm long, the females longer with less dense flowers, bearing red styles forming fruiting catkins 30 – 50 cm long, the green, winged, nuts approximately 1.8 cm wide. The species is fast growing and grows best on flat ground or shallow slopes near river banks and in deep moist soils. The climate associated with the distribution of this tree includes mild winters and mild humid summers. It generally grows in mixed stands with other species and rarely grows in pure stands. Fossils of "Pterocarya fraxinifolia" have been described