Subordinate Taxa
Scientific Name:

Deciduous, monoecious trees or shrubs with scaly buds.  Lvs alternate, simple;  stipules usually caducous.  Fls wind-pollinated, the sexes in different infls, often produced before the lvs;  ♂ fls in pendulous catkins;  fls 2–3 in axil of each bract;  each group of fls with 2–4 bracteoles;  perianth minute, 4-lobed;  stamens 2 or 4.  ♀ fls in erect catkins;  bracts and bracteoles as in male fls;  fls 2–3 in axil of each bract;  perianth 0.  Ovary superior, 2-celled.  Styles 2, free. Ovules 1 per cell, pendulous.  Fr. a compressed nutlet, usually winged, 1–3 in the axis of scales formed from the fusion of bracts and bracteoles, the whole forming a cylindric, ellipsoid or ovoid cone-like structure. Seed non-endospermic, with straight embryo.

[From:  Webb et al. (1988) Flora of New Zealand. Volume 4.]

Number of species in New Zealand within Betulaceae
Exotic: Fully Naturalised4
Exotic: Casual2
Cronquist, A. 1988: The evolution and classification of flowering plants. The New York Botanic Gardens, New York.
Mabberley, D.J. 2008: Mabberley's plant book, a portable dictionary of plants, their classification and uses. Edition 3. Cambridge University Press.