Nothofagus Blume

♂ up to 5 per spike; bracts ∞, caducous; per. campanulate, stamens 8-36. ♀ 1-3 on arrested spikes surrounded by involucre (cupule) hardening in fr.; per. minute, toothed; ovules pend.; nut 3-2-celled. Monoec. trees or shrubs with evergreen or deciduous lvs and caducous stipules. Genus of some 20 spp. of New Guinea, New Caledonia, Australia, N.Z. and temperate South America. The N.Z. spp. are endemic, with evergreen lvs, pubescent branchlets and petioles; lenticels us. conspicuous. Infls (staminate often reduced to a single fl.) in axils of uppermost scales and lowermost lvs of vegetative branchlets produced in spring, ♀ above ♂. The colour of the anthers is constant on the individual tree.

The ecological range of Nothofagus is defined by an everwet climate from the cold subantarctic and temperate-montane to tropical-montane and tropical thermo-ecological conditions; lowland tropical species are found in New Caledonia and descent of Nothofagus to c. 600 m is observed in New Britain and to 750 m in the mainland of New Guinea and d'Entrecasteaux Is.As other Fagaceae, Nothofagus shows a distinct social occurrence, past and present, mostly gaining dominance or co-dominance, as usual in the family, to which the occurrence in the montane forest in New Guinea makes no exception. The impression is gained that this is largely due to the symbiosis with ectomycorrhiza (cf STEEN. Blumea 19 1971 72 ).Nothofagus is found susceptible to fire, and does not possess fire-resistant characters.Pollination is by wind and protandry seems to prevail. Anthesis occurs simultaneously and enormous quantities Of pollen are produced which under certain conditions are observed (in New Zealand) to form clouds above the forest. Scattered pollen grains have been found at thousands of miles from the source area in windy austral areas.A symbiont of the crown, viz all species of the genus Cyttaria (Discomycetes), occurs throughout its range except in New Guinea and New Caledonia.Dispersal of the nuts of Nothofagus is very restricted and very slow. HOLLOWAY (1954) has shown that Nothofagus cannot stand transport by seawater. The nuts are compressed or triangular, possess mostly a sharp border, but are not provided with any special means of dispersal. They are rather small, but dispersal by wind will not carry them far. PREEST (1963) estimated the absolute maximum dispersal distance at c. 2-3 km and concluded that long-distance dispersal, either by wind, by birds, or by ice-bergs is excluded. In New Guinea KALKMAN & VINK (1970) found dispersal and regeneration confined to the stands. Consequently dispersal, past and present, seems to be bound to close distance of land.