This first study of the whole genus Agathis makes use of recent local revisions of the New Caledonian and Australian species which are all maintained. The male cone is shown to have most of the taxonomically useful variation, and this confirms the findings of two partial revisions centred on Indonesian species. Thirteen species are recognized, two of which have two subspecies. New Caledonia has five, and Australia three, sympatric species. Otherwise the species are allopatric except for a few populations of central Malesian A. dammara within the range of west Malesian A. borneensis. One of these montane populations is the distinctive A. dammara subsp.flavescens of Malaya, formerly a full species. Two groups and three individually distinctive species can be recognized on microsporophyll characters. The larger, group B, comprizes eight species, A. australis (New Zealand), A. corbassonii, A. lanceolata and A. montana (New Caledonia), A. macrophylla (Melanesian islands and including A. obtusa and A. vitiensis), A. atropurpurea (Australia), A. dammara (mainly central Malesia) and A. borneensis (west Malesia); both the last have long synonymies. The smaller species, group (A), comprises A. microstachya (Australia) and A. labillardieri (west New Guinea and the Sepik basin). The individually distinctive species are A. moorei and A. ovata of New Caledonia and A. robusta of Australia with its new subspecies nesophila, described here, of eastern New Guinea and New Britain.
WHITMORE, T.C. (1980). A monograph of Agathis. Plant Systematics and Evolution. 135 (1-2) pp. 41-69. [DOI: 10.1007/BF00983006]