The Podocarpaceae show great diversity, both morphologically and ecologically. Members occur mainly in the Southern Hemisphere, with most genetic variety taking place in New Caledonia, New Zealand, and Tasmania. Species diversity of
Podocarpus is found mainly in South America and the Indonesian islands, the latter also being rich in
Dacrydium and
Dacrycarpus species.
Podocarpus (with 82 to 100 species) and
Dacrydium (with 21 species) are the largest genera. A few genera are common to New Zealand and South America, supporting the view that podocarps had an extensive distribution over southern
Gondwanaland. The breaking up of Gondwanaland led to large-scale
speciation of the Podocarpaceae. Until 1970, only seven Podocarpaceae genera were accepted:
Podocarpus,
Dacrydium,
Phyllocladus,
Acmopyle,
Microcachrys,
Saxegothaea, and
Pherosphaera. All four of the African species fell under
Podocarpus –
P. falcatus,
P. elongatus,
P. henkelii, and
P. latifolius. Taxonomists divided
Podocarpus species into eight species groups based on leaf anatomy:
Afrocarpus J.Buchholz & N.E.Gray,
Dacrycarpus Endl.,
Eupodocarpus Endl.,
Microcarpus Pilg.,
Nageia (
Gaertn.)
Endl.,
Polypodiopsis C.E.Bertrand (non
Polypodiopsis Carriére nom. rej. prop. 6),
Stachycarpus Endl. and
Sundacarpus J.Buchholz and
N.E.Gray. Studies of embryology, gametophyte development, female cone structure, and cytology led to the belief that the eight categories probably deserved generic status. Researchers agreed on the need to recognize "fairly natural groupings which prove to have good geographic and probably evolutionary cohesion" and took the necessary steps to raise each section to generic status. In 1990, a
treatment of the Podocarpaceae accepted 17 genera, excluding
Phyllocladus from the family, while recognizing
Sundacarpus, but not
Manoao. In 2002, a
molecular phylogenetic study showed
Sundacarpus is
embedded in
Prumnopitys and the
monophyly of
Lagarostrobos is doubtful if
Manoao is included within it. ==Evolution==