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Podocarpus
Podocarpus neriifolius
Scientific classification
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Genus:
Podocarpus

Type species
Podocarpus elongatus
Persoon
Species

about 104-107 species, see list

Podocarpus (/ˌpdəˈkɑːrpəs/;[1] from the Greek, podos, meaning "foot", and karpos, meaning "fruit") is a genus of conifers, the most numerous and widely distributed of the podocarp family, Podocarpaceae. Podocarpus are evergreen shrubs or trees usually from 1 to 25 meters tall, known to reach 40 meters at times. The leaves are 0.5 to 15 cm long, lanceolate to oblong or falcate (sickle-shaped) in some species, with a distinct midrib. They are arranged spirally, though in some species twisted to appear in two horizontal ranks. The cones have two to five fused scales, of which only one, rarely two, are fertile, each fertile scale has one apical seed. At maturity, the scales become berry-like, swollen, brightly coloured red to purple and fleshy, and are eaten by birds which then disperse the seeds in their droppings. The male (pollen) cones are 5 to 20 mm long, often clustered several together. Many species, though not all, are dioecious. There are approximately 104 to 107 species in the genus.[2][3][4]

Podocarpus macrophyllus with mature seed cones

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 like Acacia and Eucalyptus became predominant, and the old Antarctic flora retreated to pockets that presently cover only 2% of the continent. As Australia drifted north toward Asia, the collision pushed up the Indonesian archipelago and the mountains of New Guinea, which allowed podocarp species to hop across the narrow straits into humid Asia, with P. macrophyllus reaching north to southern China and Japan. 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

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There are two subgenera, subgenus Podocarpus and subgenus Foliolatus, distinguished by cone and seed morphology.

P. henkelii

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 genus Podocarpus now assigned to other genera. A sequence of classification schemes have 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

Allergenic potential

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Male Podocarpus 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.[5]

Podocarpus are 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.[5]

Uses

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Several species of Podocarpus are grown as garden trees, or trained into hedges, espaliers, or screens. 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-fruited shrub. Some members of the genera Nageia, Prumnopitys and Afrocarpus are marketed under the genus name Podocarpus.

The red, purple or bluish fleshy 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. However, they are slightly toxic and should be eaten only in small amounts, especially when raw. Tolerates drought, deer, disease, seaside[6]

Some species of Podocarpus are used in systems of traditional medicine for conditions such as fevers, coughs, arthritis, sexually transmitted diseases, and canine distemper.[7]

A chemotherapy drug used in treatment of leukemia is made from Podocarpus.[5]

References

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  1. ^ Sunset Western Garden Book, 1995:606–607
  2. ^ Podocarpus. The Gymnosperm Database. 2013.
  3. ^ Ornelas, J. F., et al. (2010). Phylogeography of Podocarpus matudae (Podocarpaceae): pre-Quaternary relicts in northern Mesoamerican cloud forests. Journal of Biogeography 37, 2384-96.
  4. ^ Barker, N. P., et al. (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(11 & 12), 629-32.
  5. ^ a b c Ogren, Thomas (2015). The Allergy-Fighting Garden. Berkeley, CA: Ten Speed Press. p. 171-172. ISBN 978-1-60774-491-7.
  6. ^ Data sheet - Podocarpus -budgetplants.com [1]
  7. ^ Abdillahi, H. S., et al. (2011). Anti-inflammatory, antioxidant, anti-tyrosinase and phenolic contents of four Podocarpus species used in traditional medicine in South Africa. Journal of Ethnopharmacology 136(3), 496-503.

Further reading

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  • 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. ISBN 978-1-84246-025-2

Category:Podocarpaceae genera