Podocarpus

''Podocarpus'' () is a genus of conifers, the most numerous and widely distributed of the podocarp family, the Podocarpaceae. The name comes from Greek πούς (poús, “foot”) + καρπός (karpós, “fruit”). ''Podocarpus'' species are evergreen shrubs or trees, usually from tall, known to reach at times. The cones have two to five fused cone scales, which form a fleshy, berry-like, brightly coloured receptacle at maturity. The fleshy cones attract birds, which then eat the cones and disperse the seeds in their droppings. About 97 to 107 species are placed in the genus depending on the circumscription of the species.Earle, Chris J.
''Podocarpus''.
The Gymnosperm Database. 2013.

Species are cultivated as ornamental plants for parks and large gardens. The cultivar 'County Park Fire' has won the Royal Horticultural Society's Award of Garden Merit.

Names and etymology

Common names for various species include "yellowwood" and "pine", as in the plum pine (''Podocarpus elatus'') or the Buddhist pine (''Podocarpus macrophyllus'').

Description

''Podocarpus'' species are evergreen woody plants. They are generally trees, but may also be shrubs. The trees can reach a height of 40 meters at their tallest. Some shrubby species have a decumbent growth habit. The primary branches form pseudowhorls around the trunk. The bark can be scaly or fibrous and peeling with vertical strips. Terminal buds are distinctive with bud scales that are often imbricate and can be spreading.

The leaves are simple and flattened, and may be sessile or short petiolate. The phyllotaxis or leaf arrangement is spiral, and may be subopposite on some shoots. The leaves are usually linear-lanceolate or linear-elliptic in shape, though they can be broader lanceolate, ovate, or nearly elliptic in some species. Juvenile leaves are often larger than adult leaves, though similar in shape. The leaves are coriaceous and have a distinct midrib. The stomata are usually restricted to the abaxial or underside of the leaf, forming two stomatal bands around the midrib.

''Podocarpus'' spp. are generally dioecious, with the male pollen cones and female seed cones borne on separate individual plants, but some species may be monoecious. The cones develop from axillary buds, and may be solitary or form clusters.

The pollen cones are long and catkin-like in shape. They may be sessile or short pedunculate. A pollen cone consists of a slender rachis with numerous spirally arranged microsporophylls around it. Each triangular microsporophyll has two basal pollen-producing pollen sacs. The pollen is bisaccate.

The seed cones are highly modified with the few cone scales swelling and fusing at maturity. The cones are pedunculate and often solitary. The seed cone consists of two to five cone scales of which only the uppermost one or rarely two nearest the apex of the cone are fertile. Each fertile scale usually has one apical ovule. The infertile basal scales fuse and swell to form a succulent, usually brightly colored receptacle. Each cone generally has only one seed, but may have two or rarely more. The seed is attached to the apex of the receptacle. The seed is entirely covered by a fleshy modified scale known as an epimatium. The epimatium is usually green, but may be bluish or reddish in some species.

Podocarpus henkelii 2.jpg, Leaves of ''P. henkelii''
Podocarpus macrophyllus flower.jpg, Male cones of ''P. macrophyllus'' grow in clusters.
PodocarpusTotara.jpg, A seed cone of ''P. totara'' showing a red receptacle and a green epimatium
Podocarpus elatus on sand.JPG, A seedling of ''P. elatus''

Distribution

The natural distribution of the genus consists of much of Africa, Asia, Australia, Central and South America, and several South Pacific islands. The genus occurs from southern Chile north to Mexico in the Americas and from New Zealand north to Japan in the Asia-Pacific region.

''Podocarpus'' and the Podocarpaceae were endemic to the ancient supercontinent of Gondwana, which broke up into Africa, South America, India, Australia-New Guinea, New Zealand, and New Caledonia between 105 and 45 million years ago. ''Podocarpus'' is a characteristic tree of the Antarctic flora, which originated in the cool, moist climate of southern Gondwana, and elements of the flora survive in the humid temperate regions of the former supercontinent. As the continents drifted north and became drier and hotter, podocarps and other members of the Antarctic flora generally retreated to humid regions, especially in Australia, where sclerophyll genera such as ''Acacia'' and ''Eucalyptus'' became predominant. The flora of Malesia, which includes the Malay peninsula, Indonesia, the Philippines, and New Guinea, is generally derived from Asia, but includes many elements of the old Gondwana flora, including several other genera in the Podocarpaceae (''Dacrycarpus, Dacrydium, Falcatifolium, Nageia, Phyllocladus,'' and the Malesian endemic ''Sundacarpus''), and also '' Agathis'' in the Araucariaceae.

Classification

The two subgenera, ''Podocarpus'' and ''Foliolatus'', are distinguished by cone and seed morphology.

In ''Podocarpus'', the cone is not subtended by lanceolate bracts, and the seed usually has an apical ridge. Species are distributed in the temperate forests of Tasmania, New Zealand, and southern Chile, with a few occurring in the tropical highlands of Africa and the Americas.

In ''Foliolatus'', the cone is subtended by two lanceolate bracts ("foliola"), and the seed usually lacks an apical ridge. The species are tropical and subtropical, concentrated in eastern and southeastern Asia and Malesia, overlapping with subgenus ''Podocarpus'' in northeastern Australia and New Caledonia.

Species in family Podocarpaceae have been reshuffled a number of times based on genetic and physiological evidence, with many species formerly assigned to ''Podocarpus'' now assigned to other genera. A sequence of classification schemes has moved species between ''Nageia'' and ''Podocarpus'', and in 1969, de Laubenfels divided the huge genus ''Podocarpus'' into ''Dacrycarpus, Decussocarpus'' (an invalid name he later revised to the valid ''Nageia''), ''Prumnopitys'', and ''Podocarpus''.

Some species of genus ''Afrocarpus'' were formerly in ''Podocarpus'', such as ''Afrocarpus gracilior''.

;Species
* Subgenus ''Podocarpus''
** section ''Podocarpus'' (eastern and southern Africa)
*** ''Podocarpus elongatus''
*** ''Podocarpus latifolius''
*** ''Podocarpus milanjianus''
** section ''Scytopodium'' (Madagascar, eastern Africa)
*** '' Podocarpus capuronii''
*** ''Podocarpus henkelii''
*** '' Podocarpus humbertii''
*** '' Podocarpus madagascariensis''
*** '' Podocarpus rostratus''
** section ''Australis'' (southeast Australia, New Zealand, New Caledonia, southern Chile)
*** ''Podocarpus alpinus''
*** '' Podocarpus gnidioides''
*** '' Podocarpus laetus''
*** ''Podocarpus lawrencei''
*** '' Podocarpus nivalis''
*** ''Podocarpus nubigenus''
*** ''Podocarpus totara''
** section ''Crassiformis'' (northeast Queensland)
*** '' Podocarpus smithii''
** section ''Capitulatis'' (central Chile, southern Brazil, the Andes from northern Argentina to Ecuador)
*** '' Podocarpus aracensis''
*** '' Podocarpus glomeratus''
*** ''Podocarpus lambertii''
*** ''Podocarpus parlatorei''
*** '' Podocarpus salignus''
*** '' Podocarpus sellowii''
*** ''Podocarpus sprucei''
*** '' Podocarpus transiens''
**section ''Pratensis'' (southeast Mexico to Guyana and Peru)
*** ''Podocarpus oleifolius''
*** ''Podocarpus pendulifolius''
*** '' Podocarpus tepuiensis''
**section ''Lanceolatis'' (southern Mexico, Puerto Rico, Lesser Antilles, Venezuela to highland Bolivia)
*** ''Podocarpus coriaceus''
*** '' Podocarpus matudae''
*** '' Podocarpus rusbyi''
*** '' Podocarpus salicifolius''
*** '' Podocarpus steyermarkii''
**section ''Pumilis'' (southern Caribbean islands and Guiana Highlands)
*** '' Podocarpus angustifolius''
*** ''Podocarpus aristulatus''
*** '' Podocarpus buchholzii''
*** '' Podocarpus roraimae''
*** '' Podocarpus urbanii''
**section ''Nemoralis'' (central and northern South America, south to Bolivia)
*** '' Podocarpus brasiliensis''
*** '' Podocarpus celatus''
*** '' Podocarpus guatemalensis''
*** '' Podocarpus magnifolius''
*** ''Podocarpus purdieanus''
*** ''Podocarpus trinitensis''
* Subgenus ''Foliolatus''
** section ''Foliolatus'' (Nepal to Sumatra, the Philippines, and New Guinea to Tonga)
*** '' Podocarpus archboldii''
*** ''Podocarpus beecherae''
*** ''Podocarpus borneensis''
*** '' Podocarpus deflexus''
*** '' Podocarpus epiphyticus''
*** '' Podocarpus insularis''
*** '' Podocarpus levis''
*** ''Podocarpus neriifolius''
*** '' Podocarpus novae-caledoniae''
*** ''Podocarpus pallidus''
*** '' Podocarpus rubens''
*** '' Podocarpus spathoides''
** section ''Acuminatus'' (northern Queensland, New Guinea, New Britain, Borneo)
*** ''Podocarpus dispermus''
*** '' Podocarpus ledermannii''
*** '' Podocarpus micropedunculatus''
** section ''Globulus'' (Taiwan to Vietnam, Sumatra and Borneo, and New Caledonia)
*** ''Podocarpus annamiensis''
*** '' Podocarpus globulus''
*** '' Podocarpus lucienii''
*** ''Podocarpus nakaii''
*** '' Podocarpus sylvestris''
*** '' Podocarpus teysmannii''
**section ''Longifoliolatus'' (Sumatra and Borneo, east to Fiji)
*** ''Podocarpus atjehensis''
*** '' Podocarpus bracteatus''
*** '' Podocarpus confertus''
*** '' Podocarpus decumbens''
*** '' Podocarpus degeneri''
*** '' Podocarpus gibbsii''
*** '' Podocarpus longefoliolatus''
*** '' Podocarpus polyspermus''
*** '' Podocarpus pseudobracteatus''
*** '' Podocarpus salomoniensis''
**section ''Gracilis'' (southern China, across Malesia to Fiji)
*** '' Podocarpus affinis''
*** '' Podocarpus glaucus''
*** '' Podocarpus lophatus''
*** '' Podocarpus pilgeri''
*** '' Podocarpus rotundus''
** section ''Macrostachyus'' (Southeast Asia to New Guinea)
*** '' Podocarpus brassii''
*** '' Podocarpus brevifolius''
*** '' Podocarpus costalis''
*** '' Podocarpus crassigemmis''
*** '' Podocarpus tixieri''
** section ''Rumphius'' (Hainan, south through Malesia to northern Queensland)
*** ''Podocarpus grayae'' (aka ''P. grayii'' and ''P. grayi'')
*** ''Podocarpus laubenfelsii''
*** '' Podocarpus rumphii''
** section ''Polystachyus'' (southern China and Japan, through Malaya to New Guinea and northeast Australia)
*** ''Podocarpus chinensis''
*** '' Podocarpus chingianus''
*** ''Podocarpus elatus''
*** '' Podocarpus fasciculus''
*** '' Podocarpus macrocarpus''
*** ''Podocarpus macrophyllus''
*** '' Podocarpus polystachyus''
*** '' Podocarpus ridleyi''
*** '' Podocarpus subtropicalis''
** section ''Spinulosus'' (southeast and southwest coasts of Australia)
*** ''Podocarpus drouynianus''
*** '' Podocarpus spinulosus''

Allergenic potential

Male ''Podocarpus'' spp. are extremely allergenic, and have an OPALS allergy-scale rating of 10 out of 10. Conversely, completely female ''Podocarpus'' plants have an OPALS rating of 1, and are considered "allergy-fighting", as they capture pollen while producing none.

''Podocarpus'' is related to yews, and as with yews, the stems, leaves, flowers, and pollen of ''Podocarpus'' are all poisonous. Additionally, the leaves, stems, bark, and pollen are cytotoxic. The male ''Podocarpus'' blooms and releases this cytotoxic pollen in the spring and early summer. Heavy exposure to the pollen, such as with a male ''Podocarpus'' planted near a bedroom window, can produce symptoms that mimic the cytotoxic side effects of chemotherapy.

Uses

The earliest use of ''P. elongatus'' dates back to the southern African Middle Stone Age where it was used to produce an adhesive by distillation. Today, several species of ''Podocarpus'' are grown as garden trees, or trained into hedges, espaliers, or screens. Podocarpus trees (misspelled as "protocarpus") were used on Isla Nublar, Costa Rica, to conceal electric fences from visitors. Common garden species used for their attractive deep-green foliage and neat habits include ''P. macrophyllus'', known commonly as Buddhist pine, fern pine, or ''kusamaki'', ''P. salignus'' from Chile, and ''P. nivalis'', a smaller, red-fleshy-coned shrub. Some members of the genera ''Nageia'', ''Prumnopitys'', and ''Afrocarpus'' are marketed under the genus name ''Podocarpus''.

The red, purple, or bluish fleshy cone (popularly called a "fruit") of most species of ''Podocarpus'' are edible, raw or cooked into jams or pies. They have a mucilaginous texture with a slightly sweet flavor. They are slightly toxic, so should be eaten only in small amounts, especially when raw.

Some species of ''Podocarpus'' are used in systems of traditional medicine for conditions such as fevers, coughs, arthritis, sexually transmitted diseases, and canine distemper.

A chemotherapy drug used in treatment of leukemia is made from ''Podocarpus''.

References

Further reading

*de Laubenfels, D. J. (1985). A taxonomic revision of the genus ''Podocarpus''. ''Blumea'' 30(2), 251-78.
*Farjon, A. ''World Checklist and Bibliography of Conifers'' 2nd Edition. Kew, Richmond, UK. 2001.

{{Taxonbar, from=Q157524

Podocarpaceae genera
Dioecious plants