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The leaves turn yellow in Autumn. The flowers are wind-pollinated catkins 3–6 centimeters (1 + 1 ⁄ 4 – 2 + 1 ⁄ 4 in) long, the male catkins pendulous, the female catkins erect. The fruit is unusual among birches in maturing in late spring; it is composed of numerous tiny winged seeds packed between the catkin bracts. [2] [6] River birch ...
Agrilus anxius, the bronze birch borer, is a wood-boring buprestid beetle native to North America, more numerous in the warmer parts of the continent and rare in the north. [1] It is a serious pest on birch trees (Betula), frequently killing them. The river birch Betula nigra is the most resistant species, while other American birches are less so.
Birch dieback is a disease of birch trees that causes the branches in the crown to die off. The disease may eventually kill the tree. In an event in the Eastern United States and Canada in the 1930s and 1940s, no causal agent was found, but the wood-boring beetle, the bronze birch borer, was implicated in the severe damage and death of the tree that often followed.
The primary species affecting birch trees in North America are Profenusa thomsoni and Fenusa pumila. Areas inside the leaves are consumed by the larvae, affecting the leaves' ability to produce food. Yearly browning of birch leaves are noticed in mid July and August, but the leafminers have been feeding inside the leaf tissue since early spring.
Betula occidentalis, the water birch or red birch, is a species of birch native to western North America, in Canada from Yukon east to Northwestern Ontario and southwards, and in the United States from eastern Washington east to western North Dakota, [citation needed] and south to eastern California, northern Arizona and northern New Mexico, and southwestern Alaska.
The leaves of the silver birch tree are used in the festival of St George, held in Novosej and other villages in Albania. [24] Birch leaves in the coat of arms of Karjalohja. The birch is New Hampshire's state tree and the national tree of Finland and Russia. The yellow birch is the official tree of the province of Quebec (Canada).
These leaves usually fall before the normal leaves grow elsewhere on the tree. [3] There can be several witches broom in a tree. [4] Witches broom, formed by Taphrina betulina can be found on dwarf birch (Betula nana), Betula nana x pubescens, silver birch (Betula pendula), downy birch (Betula pubescens) and Betula pubescens var.glabrata. [1]
Betula costata - Korean birch [1] Betula nigra - River birch or black birch; Betula potaninii - Potanin's birch; Tetraploid (4n = 56). Betula albosinensis - Chinese red birch Betula albosinensis var. septentrionalis - North Chinese red birch; Betula ermanii - Erman's birch; Betula jacquemontii (B. utilis subsp. jacquemontii) - White-barked ...