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Podocarpaceae Endlicher 1847Common NamesPodocarp family, [Chinese].
Taxonomic notesAbout 15 genera and 147 species. It has been treated as an order: Podocarpales Pulle ex Reveal 1992, and many of its constituent genera, including Nageia, Phyllocladus and Saxegothaea, have been raised to the rank of Family by previous authors. Most taxonomists seem to agree that Phyllocladus is the most atypical genus in the family, and it is often treated as Phyllocladaceae Bessey 1907.DescriptionEvergreen shrubs or trees, usually with straight trunk and more or less horizontal branches. Leaves usually spirally arranged, sometimes opposite, scale-like, needle-like, or more apart, flat and leaf-like, linear to lanceolate. Monoecious or dioecious. Male strobili usually catkin-like; Stamens (=microsporophylls) numerous, close together, imbricate, each with 2 sporangia (=inverted pollen sacs); pollen grains usually winged. Female cones maturing in one year, much reduced to a few fleshy bracts or scales, pendant, usually borne on a thin peduncle, containing a single inverted ovule. Seeds completely covered by a fleshy structure referred to as an epimatium, wingless. Epimatium and integument sometimes connate and forming a leathery testa. Cotyledons 2, with 2 parallel vascular bundles (1, 2).RangeThe family is predominantly found in the Australasian region, with most taxa native from New Zealand to SE Asia. Most of species are not of wide distribution, being confined to one or a few islands, viz. Tasmania, New Zealand, New Caledonia, New Guinea, Philippines, Borneo. Some species of the genera Dacrydium, Lepidothamnus, Nageia, Podocarpus, Prumnopitys and Saxegothaea are found beyond Australasia, in India, Japan, China, Africa, the Caribbean and the New World south from Mexico to Chile. Of these, Saxegothaea, a monotypic genus found in Chile and Argentina, is the only genus with no representatives in the Australasian region. Most members of the family are trees native to wet tropical or subtropical (often, tropical mountains) forests. A few are small trees or shrubs native to forest understory environments.Big TreeOldestDendrochronologyEthnobotanyObservationsRemarksAlthough the second-largest conifer family, the Podocarpaceae are far less well-known than the other two big families, Pinaceae and Cupressaceae. There are several possible reasons for this situation. The Podocarpaceae are chiefly a tropical family, thus few species have attracted interest among the European horticultural community and few species are known for their ornamental value. The family does not otherwise possess great economic importance -- only a few species are exploited for timber, and those are for the most part greatly diminished by overcutting -- so it has not attracted attention on that score. Most species in the family are found in tropical forests that are dominated by a great many species of angiosperm trees, so the family does not possess the ecological significance attached to Pinaceae or Cupressaceae. Finally, the family is primarily found in Third World countries, where plants in general receive little research unless they be economically important. This is a regrettable state of affairs, because the Podocarpaceae probably contain more species threatened by overcutting and habitat loss than any other family. In view of the above considerations, in seems inevitable that many taxa described here are bound for extinction in the coming decades.Citations(1) Silba 1986.(2) Van Royen 1979. | |
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