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Betula pubescens

Downy birch

Downy birch, moor birch, white birch, European white birch, hairy birch (Eng), abedul (Spa), bedoll (Cat), urkia (Baq), bidueiro (Glg), vidoeiro (Por).

Native

DID YOU KNOW...? A single adult birch can produce up to 900,000,000,000 pollen grains.

DESCRIPTION

Deciduous tree that does not usually exceed 20 m in height. It has a pyramidal form and peculiar whitish bark which cracks and darkens slightly when it matures. It differs from its relative Betula pendula Roth, by its horizontally arranged branches, the tips of which do not hang down, as well as by the hairiness of the young twigs and buds. The leaves are simple, alternate, more or less diamond-shaped (occasionally somewhat heart-shaped or triangular), doubly serrated, green and shiny on the upper side, and they end in an elongated point. The male and female flowers are arranged in long, hanging, flexible clusters known as catkins, which appear at the end of autumn. The pollen is found in the male flowers. The seeds are very small and have two membranous wings of a similar width to the seed, which help its dispersion by the wind.

ECOLOGY

This tree grows along watercourses, on shady and moist slopes, areas with ponded water and peat bogs, colonising quarries and places that have been stripped of vegetation or burned. It grows from sea level up to altitudes of 2000 m, forming stands or copses, or found with other riparian plants.

DISTRIBUTION

This species lives throughout Europe and Asia. On the Iberian Peninsula, it is mainly found in the northern half, with higher densities towards the northwest. There are notable relict populations remaining in the Montes de Toledo and Sierra de Francia mountains and the Alto Tajo natural park.