Product Code Database
Podocarpaceae is a large family of mainly southern hemisphere , known in English as podocarps, comprising about 156 species of evergreen trees and shrubs.James E. Eckenwalder. 2009. Conifers of the World. Portland, Oregon: Timber Press. . It contains 20 genera if Phyllocladus is included and Manoao and Sundacarpus are recognized. The family achieved its maximum diversity in the Cenozoic, making the Podocarpaceae family one of the most diverse in the southern hemisphere.
The family is a classic member of the Antarctic flora, with its main centres of diversity in Australasia, particularly New Caledonia, Tasmania, and New Zealand, and to a slightly lesser extent Malesia and South America (primarily in the Andes Mountains). Several genera extend north of the equator into Indochina and the Philippines. Podocarpus reaches as far north as southern Japan and southern China in Asia, and Mexico in the Americas, and Nageia into southern China and southern India. Two genera also occur in Afrotropic Africa, the widespread Podocarpus and the endemic Afrocarpus.
Parasitaxus usta is unique as the only known parasitic gymnosperm. It occurs on New Caledonia, where it is parasitic on another member of the Podocarpaceae, Falcatifolium taxoides.William T. Sinclair, R. R. Mill, M. F. Gardner, P. Woltz, T. Jaffré, J. Preston, M. L. Hollingsworth, A. Ponge, and M. Möller. 2002. "Evolutionary relationships of the New Caledonian heterotrophic conifer, Parasitaxis usta (Podocarpaceae), inferred from chloroplast trnL-F intron/spacer and nuclear rDNA ITS2 sequences". Plant Systematics and Evolution 233 (1–2): 79–104.
The genus Phyllocladus is Sister taxon to the Podocarpaceae sensu stricto. It is treated by some botanists in its own family, the Phyllocladaceae.Christopher N. Page. 1990. "Phyllocladaceae" pages 317–319. In: Klaus Kubitzki (general editor); Karl U. Kramer and Peter S. Green (volume editors) The Families and Genera of Vascular Plants volume I. Berlin, Heidelberg: Springer-Verlag.
Podocarpus (with 82 to 100 species)Christopher N. Page. 1990. "Podocarpaceae" pages 332–346. In: Klaus Kubitzki (general editor); Karl U. Kramer and Peter S. Green (volume editors) The Families and Genera of Vascular Plants volume I. Berlin, Heidelberg: Springer-Verlag. 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 recognized: 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 (Joseph Gaertner) 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.Barker, N. P.; Muller, E. M.; and Mill, R. R. (2004). "A yellowwood by any other name: molecular systematics and the taxonomy of Podocarpus and the Podocarpaceae in southern Africa" . South African Journal of Science, 100: 629–632.
In 1990, a Treatise of the Podocarpaceae recognized 17 genera, excluding Phyllocladus from the family, while recognizing Sundacarpus, but not Manoao. In 1995, Manoao was segregated from Lagarostrobos, based on Plant morphology Phenotypic trait.Brian P. J. Molloy. 1995. " Manoao (Podocarpaceae), a new monotypic conifer genus endemic to New Zealand". New Zealand Journal of Botany 33 (2): 183–201. In 2002, a molecular phylogenetic study showed Sundacarpus is Paraphyly in Prumnopitys and the monophyly of Lagarostrobos is doubtful if Manoao is included within it. More recent treatments of the family have recognized Manoao, but not Sundacarpus.Aljos Farjon. 2008. A Natural History of Conifers. Portland, Oregon: Timber Press.
|
|
