Podocarpaceae
Encyclopedia
Podocarpaceae is a large family
of mainly Southern Hemisphere
conifers, comprising about 156 species
of evergreen
tree
s and shrub
s. It contains 19 genera
if Phyllocladus is included and if Manoao and Sundacarpus are recognized.
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 Indo-China 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 sub-Saharan
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
.
The genus Phyllocladus
, is sister to Podocarpaceae sensu stricto. It is treated by some botanists in its own family Phyllocladaceae.
, New Zealand
and Tasmania
. Species diversity of Podocarpus is found mainly in South America
and the Indonesia
n islands, the latter also being rich in Dacrydium and Dacrycarpus species.
Podocarpus L’Hér. ex Pers. (with 82 to 100 species) and Dacrydium Sol. ex Forst. (with 21 species) are the largest genera. A few genera are common to New Zealand
and South America
, supporting the view that the 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 recognised - 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 categories based on leaf anatomy: Afrocarpus J. Buchholz & N. E. Gray, Dacrycarpus Endl., Eupodocarpus Endl., Microcarpus Pilg., Nageia (Gaertn.) Endl., Polypodiopsis C.E. Bertrand (non Polypodiopsis Carriére nom. rej. prop.6), Stachycarpus Endl. and Sundacarpus J. Buchholz & 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.
In 1990, a treatment
of Podocarpaceae recognized 17 genera, excluding Phyllocladus from the family, while recognizing Sundacarpus, but not Manoao. In 1995, Manoao was segregated
from Lagarostrobus, based on morphological
characters. In 2002, a molecular phylogenetic study
showed that Sundacarpus is embedded
in Prumnopitys and that the monophyly
of Lagarostrobos is doubtful if Manoao is included within it. More recent treatments of the family have recognized Manoao, but not Sundacarpus.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of mainly Southern Hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...
conifers, comprising about 156 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of evergreen
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
s and shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s. It contains 19 genera
Genera
Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...
if Phyllocladus is included and if Manoao and Sundacarpus are recognized.
The family is a classic member of the Antarctic flora
Antarctic flora
The Antarctic flora is a distinct community of vascular plants which evolved millions of years ago on the supercontinent of Gondwana, and is now found on several separate areas of the Southern Hemisphere, including southern South America, southernmost Africa, New Zealand, Australia and New Caledonia...
, with its main centres of diversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...
in Australasia
Australasia ecozone
The Australasian zone is an ecological region that is coincident, but not synonymous , with the geographic region of Australasia...
, particularly New Caledonia
New Caledonia
New Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...
, Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
and New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, and to a slightly lesser extent Malesia
Malesia
Malesia is a biogeographical region straddling the boundaries of the Indomalaya ecozone and Australasia ecozone, and also a phytogeographical floristic region in the Paleotropical Kingdom.-Floristic province:...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
(primarily in the Andes
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
mountains). Several genera extend north of the equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
into Indo-China and the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
. Podocarpus
Podocarpus
Podocarpus is a genus of conifers, the most numerous and widely distributed of the podocarp family Podocarpaceae. The 105 species of Podocarpus are evergreen shrubs or trees from 1-25 m in height...
reaches as far north as southern Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
and southern China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
in Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
, and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
in the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
, and Nageia
Nageia
Nageia is a genus of conifers belonging to the podocarp family Podocarpaceae. Nageia includes evergreen shrubs and trees, from one to 54 meters in height. A 2009 treatment of the genus recognized five species. Some authors consider Nageia formosensis to be a separate species from Nageia nagi,...
into southern China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
and southern India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
. Two genera also occur in sub-Saharan
Afrotropic
The Afrotropic is one of the Earth's eight ecozones. It includes Africa south of the Sahara Desert, the southern and eastern fringes of the Arabian Peninsula, the island of Madagascar, southern Iran and extreme southwestern Pakistan, and the islands of the western Indian Ocean. It was formerly...
Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, the widespread Podocarpus and the endemic Afrocarpus
Afrocarpus
Afrocarpus is a genus of conifers belonging to the podocarp family Podocarpaceae. Afrocarpus was designated a genus in 1989, when several species formerly classified in Podocarpus and Nageia were reclassified. Two to six species are recognized.As the name intimates, Afrocarpus is native to Africa...
.
Parasitaxus usta is unique as the only known parasitic gymnosperm
Gymnosperm
The gymnosperms are a group of seed-bearing plants that includes conifers, cycads, Ginkgo, and Gnetales. The term "gymnosperm" comes from the Greek word gymnospermos , meaning "naked seeds", after the unenclosed condition of their seeds...
. It occurs on New Caledonia
New Caledonia
New Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...
, where it is parasitic on another member of the Podocarpaceae, Falcatifolium taxoides
Falcatifolium taxoides
Falcatifolium taxoides is a species of conifer in the Podocarpaceae family. It is found only in New Caledonia.-References:* Conifer Specialist Group 1998. . Downloaded on 10 July 2007....
.
The genus Phyllocladus
Phyllocladus
Phyllocladus is a small genus of conifers, now usually treated in the family Podocarpaceae. They are morphologically very distinct from the other genera in that family, and some botanists treat them in a family of their own, the Phyllocladaceae. One molecular phylogenetic analysis found...
, is sister to Podocarpaceae sensu stricto. It is treated by some botanists in its own family Phyllocladaceae.
Taxonomy
The Podocarpaceae family shows great diversity, both morphologically and ecologically. Its members occur mainly in the southern hemisphere, with most generic variety taking place in New CaledoniaNew Caledonia
New Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...
, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
and Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
. Species diversity of Podocarpus is found mainly in South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
and the Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
n islands, the latter also being rich in Dacrydium and Dacrycarpus species.
Podocarpus L’Hér. ex Pers. (with 82 to 100 species) and Dacrydium Sol. ex Forst. (with 21 species) are the largest genera. A few genera are common to New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, supporting the view that the Podocarps had an extensive distribution over southern Gondwanaland. The breaking up of Gondwanaland led to large-scale speciation
Speciation
Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages...
of the Podocarpaceae.
Until 1970 only seven Podocarpaceae genera were recognised - 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 categories based on leaf anatomy: Afrocarpus J. Buchholz & N. E. Gray, Dacrycarpus Endl., Eupodocarpus Endl., Microcarpus Pilg., Nageia (Gaertn.) Endl., Polypodiopsis C.E. Bertrand (non Polypodiopsis Carriére nom. rej. prop.6), Stachycarpus Endl. and Sundacarpus J. Buchholz & 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.
In 1990, a treatment
Treatise
A treatise is a formal and systematic written discourse on some subject, generally longer and treating it in greater depth than an essay, and more concerned with investigating or exposing the principles of the subject.-Noteworthy treatises:...
of Podocarpaceae recognized 17 genera, excluding Phyllocladus from the family, while recognizing Sundacarpus, but not Manoao. In 1995, Manoao was segregated
Segregate (taxonomy)
In taxonomy, a segregate, or a segregate taxon is created when a taxon is split off, from another taxon. This other taxon will be better known, usually bigger, and will continue to exist, even after the segregate taxon has been split off...
from Lagarostrobus, based on morphological
Plant morphology
Plant morphology or phytomorphology is the study of the physical form and external structure of plants. This is usually considered distinct from plant anatomy, which is the study of the internal structure of plants, especially at the microscopic level...
characters. In 2002, a molecular phylogenetic study
Research
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...
showed that Sundacarpus is embedded
Paraphyly
A group of taxa is said to be paraphyletic if the group consists of all the descendants of a hypothetical closest common ancestor minus one or more monophyletic groups of descendants...
in Prumnopitys and that the monophyly
Monophyly
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...
of Lagarostrobos is doubtful if Manoao is included within it. More recent treatments of the family have recognized Manoao, but not Sundacarpus.
Sources
- Christopher J. Quinn and Robert A. Price. 2003. "Phylogeny of the Southern Hemisphere Conifers". Proceedings of the Fourth International Conifer Conference:129-136.