Podocarpaceae (Podocarps) description

Acmopyle pancheri (van Gelderen et al. 1986) is a tropical forest understory shrub or tree.

Afrocarpus falcatus is one of the few popular ornamental podocarps.

Dacrydium cupressinum is a magnificent emergent tree of the New Zealand forest.

Dacrycarpus dacrydioides showing the characteristic fruit and seed of a podocarp.

Halocarpus bidwillii is an alpine shrub.

Lepidothamnus laxifolius is probably the world's smallest conifer; mature cones have been found on plants less than 7.6 cm tall.

Microstrobos fitzgeraldi is a small shrub that only grows by waterfalls [Trevor Hinchliffe].

Nageia nagi is a culturally important tree of Japan, China and Vietnam [Tom Velardi].

Parasitaxus ustus is the only known parasitic gymnosperm.

The "leaves" of Phyllocladus toatoa are actually flattened stems [Trevor Hinchliffe].

Podocarpus totara includes the largest tree in the Podocarpaceae.

Prumnopitys taxifolia is a large tree in the New Zealand rainforest.

Podocarpaceae

Endlicher 1847

Common names

Podocarp family, [Chinese].

Taxonomic notes

In this treatment, 18 genera and 173 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.

Many of the genera described here were originally lumped into the huge catchall genus Podocarpus or the also-very-large genus Dacrydium, and appear as such in much of the literature. Here is a brief and simplified chronology of how the podocarps have been subdivided at the generic rank:

1786 - Solander	Dacrydium described.
1788 - Gaertner	Nageia described, begins a long and complex history (mostly 1840 to 1990) with the net result of species being moved from Podocarpus into Nageia.
1807 - L'Heritier	Podocarpus described, begins accumulating species, a process that continues today.
1825 - Richard	Phyllocladus described. No one ever confuses with it any of the other podocarps.
1845 - Hooker f.	Microcachrys described.
1850 - Archer	Pherosphaera described, lumping several new species with Microcachrys.
1851 - Lindley	Saxegothaea described.
1861 - Phil.	Prumnopitys described but is monotypic for 117 years.
1903 - Pilger	Acmopyle described.
1951 - Garden et Johnson	Microstrobos segregated from Pherosphaera; Pherosphaera reverts to Microcachrys.
1969 - de Laubenfels	Nageia species reassigned to the new genus Decussocarpus Dacrycarpus segregated from Podocarpus Falcatifolium described, mostly with new species.
1972 - de Laubenfels	Parasitaxus described.
1978 - de Laubenfels	Seven Podocarpus species assigned to Prumnopitys.
1982 - Quinn	Halocarpus, Lagarostrobos, and Lepidothamnus segregated from Dacrydium.
1987 - de Laubenfels	Decussocarpus invalidated and its species reassigned to Nageia.
1989 - Page	Afrocarpus segregated from Nageia and Podocarpus Retrophyllum segregated from Nageia Sundacarpus segregated from Prumnopitys.
1995 - Molloy	Manoao segregated from Lagarostrobos.

Description

Evergreen 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. Pollen cones usually catkin-like; stamens numerous, close together, imbricate, each with 2 sporangia; 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 (Van Royen 1979, Silba 1986).

All investigated Podocarpaeceae have vesicular-arbuscular mycorrhizas (Newman and Reddell 1987, Brundrett 2008 and citations therein).

Range

The 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 tree

The totara, Podocarpus totara.

Oldest

Quite possibly the rimu, Dacryium cupressinum, but there are several other species, possibly equally old or older, that have not been well studied.

Dendrochronology

Ethnobotany

Although 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. With few and local exceptions (e.g., New Zealand), 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. 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 the 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.

Observations

See the generic and species descriptions.

Remarks

Netta E. Gray did much of the early work on Podocarpus and its segregates (Afrocarpus, Nageia, Prumnopitys, Retrophyllum, and Sundacarpus). She was accordingly honored by D.J. de Laubenfels, the current grand old man of the Podocarpaceae, with Podocarpus grayae de Laub. 1985. The September 1973 Plant Science Bulletin carried this brief biography of Mrs. Gray:

Netta E. Gray worked and studied with John T. Buchholz at the University of Illinois, completing her Masters degree in Botany. She was particularly interested in the genus Podocarpus. The work she started with Buchholz and later carried on herself was a careful systematic treatment of each of the sections of Podocarpus. She was concerned with the systematic importance of anatomical details, and the geographical distribution and evolution of the genus. As a result of her diligent study of the group she became one of the world's authorities on this genus and had such visitors as R. Florin come to her door. She lived with her husband Professor Stephen W. Gray near Atlanta, Georgia and taught at Agnes Scott College in Decatur, Georgia. She continued an active interest in research and publication about the genus, Podocarpus, as well as the Gymnosperms as a whole, until her death on August 24, 1970.

Citations

Brundrett, Mark. 2008. Mycorrhizal Associations: The Web Resource. mycorrhizas.info, accessed 2009.06.09.

Newman, E.I. and P. Reddell. 1987. The distribution of mycorrhizas among families of vascular plants. New Phytologist 106: 745-751.