Betula populifolia the female catkins erect. The fruit, maturing in autumn, is composed of many tiny winged seeds packed between the catkin bracts. The wood is medium hard and is used for high grade plywood, furniture, drum shells, spools and firewood. Like other North American birches, gray birch is highly resistant to the Bronze birch borer ("Agrilus anxius"). The leaves of the gray birch serve as food for various Lepidoptera, such as the leaf miner moth "Cameraria betulivora". Between about 1930 and 1950, many gray birch trees, along with paper birch and yellow birch ("Betula alleghaniensis"), were affected and killed by birch
Fokienia Tuyên Quang, Yên Bái and Vĩnh Phú), west central Vietnam (provinces of Đắk Lắk, Gia Lai, Lâm Đồng), and west to northern Laos. The name derives from the old Romanised name of Fujian province, China, from where the first specimen was introduced to Europe, collected by Captain Hodgins in 1908. "Fokienia" is an evergreen tree, 25–30 m tall. It has greyish-brownish bark that peels off when the tree is young. On older trees, the bark presents longitudinal fissures and becomes aromatic. The leaves are arranged in flattened branchlet systems, with the branchlets in one plane. The leaves on adult trees