T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Betula pendula (Silver birch)

Kingdom:   Plantae
(unranked):        Angiosperms
(unranked):        Eudicots
(unranked):        Rosids
Order:       Fagales
Family:      Betulaceae
Genus:      Betula
Subgenus:  Betula
Species:     B. pendula
Binomial name: Betula pendula
Common names: Silver birch, Warty birch, European white birch.

Betula pendula is a small to a medium-sized deciduous tree that grows up to 25m + tall and has an open crown. It is native to Europe and parts of Asia. In some areas of New Zealand, it is a weed plant because it will form a dense canopy which suppresses the growth of low growing native species.
It can be found growing usually in wild in wet areas of NorthIsland and the upper South Island. It grows on roadsides, open areas and wastelands.   
The straight trunk has smooth, papery, silver-white bark which darkens and develops narrow vertical furrows on mature trees. Betula pendula have drooping branches. The deltiod shaped leaves are up to 6 cm long and 5.5 cm wide and have with 5-7 pairs of veins. The margins are coarsely toothed.
It flowers during September to November. The trees inflorescences are catkins which develop at a leaf axil. The pendulous male catkins are up to 9 cm long and female catkins are about 2.5 cm. The tiny separate green, male and female flowers are each only 2-4 mm long.
The seeds are 1.5-2.5 mm long, with a large wing and are wind spread. The tree will also spread by suckering in wetlands.

The underside of a leaf.

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/