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
Eucalyptus deglupta flower buds contain stamens and pistil and are usually pollinated via bee. After fertilization, the flower capsule becomes a woody fruit, known as a gum nut, which contains the seeds. The unique multi-hued bark is the most distinctive feature of the tree. Patches of outer bark are shed annually at different times, showing a bright green inner bark. This then darkens and matures to give blue, purple, orange and then maroon tones. The previous season’s bark peels off in strips to reveal a brightly colored new bark below. The peeling process results in vertical streaks of red, orange, green, blue,