Araucariaceae – also known as araucarians – is an extremely ancient family of coniferous trees. The family achieved its maximum diversity during the
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...
and
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
periods and the early
Cenozoic
The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configura ...
, when it was distributed almost worldwide.
Most of the Araucariaceae in the
Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...
vanished in the
Cretaceous–Paleogene extinction event
The Cretaceous–Paleogene (K–Pg) extinction event (also known as the Cretaceous–Tertiary extinction) was a sudden mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million years ago. With the ...
, and they are now largely confined to the
Southern Hemisphere, except for a few species of ''
Agathis
''Agathis'', commonly known as kauri or dammara, is a genus of 22 species of evergreen tree. The genus is part of the ancient conifer family Araucariaceae, a group once widespread during the Jurassic and Cretaceous periods, but now largely re ...
'' in
Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...
.
Description
![00 29 0496 Waipoua Forest NZ - Kauri Baum Tane Mahuta](https://upload.wikimedia.org/wikipedia/commons/5/5e/00_29_0496_Waipoua_Forest_NZ_-_Kauri_Baum_Tane_Mahuta.jpg)
Members of Araucariaceae are typically extremely tall
evergreen
In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...
trees,
reaching heights of or more.
They can also grow very large stem diameters; a
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
kauri
''Agathis'', commonly known as kauri or dammara, is a genus of 22 species of evergreen tree. The genus is part of the ancient conifer family Araucariaceae, a group once widespread during the Jurassic and Cretaceous periods, but now largely res ...
tree (''
Agathis australis
''Agathis australis'', commonly known by its Māori name kauri (), is a coniferous tree in the family ''Araucariaceae'', found north of 38°S in the northern regions of New Zealand's North Island.
It is the largest (by volume) but not t ...
'') named ''
Tāne Mahuta
Tāne Mahuta, also called "God of the Forest", is a giant Agathis australis, kauri tree (''Agathis australis'') in the Waipoua Forest of Northland Region, New Zealand. Its age is unknown but is estimated to be between 1,250 and 2,500 years. It i ...
'' ("The Lord of the Forest") has been measured at tall with a
diameter at breast height
Diameter at breast height, or DBH, is a standard method of expressing the diameter of the trunk or bole of a standing tree. DBH is one of the most common dendrometric measurements.
Tree trunks are measured at the height of an adult's breast, ...
of . Its total wood volume is calculated to be ,
making it the third-largest conifer after ''
Sequoia'' and ''
Sequoiadendron
''Sequoiadendron'' is a genus of evergreen trees, with two species, only one of which survives to the present:
* ''Sequoiadendron giganteum'', extant, commonly known as wellingtonia, giant redwood and giant sequoia, growing naturally in the Sie ...
'' (both from the Cupressaceae subfamily
Sequoioideae
Sequoioideae, popularly known as redwoods, is a subfamily of coniferous trees within the family Cupressaceae. It includes the largest and tallest trees in the world.
Description
The three redwood subfamily genera are '' Sequoia'' from coast ...
).
The trunks are columnar and have relatively large
pith
Pith, or medulla, is a tissue in the stems of vascular plants. Pith is composed of soft, spongy parenchyma cells, which in some cases can store starch. In eudicotyledons, pith is located in the center of the stem. In monocotyledons, it ext ...
s with
resin
In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on natu ...
ous
cortices.
The branching is usually horizontal and tiered, arising regularly in whorls of three to seven branches or alternating in widely separated pairs.
The leaves can be small, needle-like, and curved, or they can be large, broadly ovate, and flattened.
They are spirally arranged, persistent, and usually have
parallel venation.
Like other conifers, they produce
cones
A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex.
A cone is formed by a set of line segments, half-lines, or lines conn ...
. Each tree can have both male and female cones (
monoecious
Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy.
Monoecy is conne ...
) or they can have only male or female cones (
dioecious
Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...
).
Male cones are among the largest among all conifer cones, on average. They are cylindrical and drooping, somewhat resembling
catkin
A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind-pollinated (anemophilous) but sometimes insect-pollinated (as in ''Salix''). They contain many, usually unisexual flowers, arranged cl ...
s. They are borne singly on the tips of branches or the
axil
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...
s of leaves. They contain numerous
sporophyll
A sporophyll is a leaf that bears sporangia. Both microphylls and megaphylls can be sporophylls. In heterosporous plants, sporophylls (whether they are microphylls or megaphylls) bear either megasporangia and thus are called megasporophylls, or ...
s arranged in whorls or spirals. Each has four to 20 elongated
pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...
sacs attached to the lower surface at one end. The pollen grains are round and do not possess wings or air sacs.
Female cones are also very large. They are spherical to ovoid in shape and borne erect on thick, short shoots at branch tips. The numerous bracts and scales are either fused to each other or separate for half of their lengths.
The scales almost always bear only one seed on its upper surface, in contrast to two in true pines (family
Pinaceae
The Pinaceae, or pine family, are conifer trees or shrubs, including many of the well-known conifers of commercial importance such as Cedrus, cedars, firs, Tsuga, hemlocks, larches, pines and spruces. The family is included in the order Pinales, ...
).
They are very large, among the largest seeds among conifers. They are dispersed by wind, usually using wing-like structures. On maturity, the female cones detach and fall to the ground.
Due to their size, they can cause serious injuries if they hit a person. The cones of the bunya bunya, ''
Araucaria bidwillii
''Araucaria bidwillii'', commonly known as the bunya pine and sometimes referred to as the false monkey puzzle tree, is a large evergreen coniferous tree in the plant family Araucariaceae. It is found naturally in south-east Queensland Austra ...
'', for example, weigh , about the size and weight of a large
pineapple
The pineapple (''Ananas comosus'') is a tropical plant with an edible fruit; it is the most economically significant plant in the family Bromeliaceae. The pineapple is indigenous to South America, where it has been cultivated for many centuri ...
. They can drop from heights of .
Classification and genera
![Wollemia nobilis fg03](https://upload.wikimedia.org/wikipedia/commons/1/1d/Wollemia_nobilis_fg03.JPG)
Araucariaceae is classified under the
order Pinales
The order Pinales in the division Pinophyta, class Pinopsida, comprises all the extant conifers. The distinguishing characteristic is the reproductive structure known as a cone produced by all Pinales. All of the extant conifers, such as cedar, ...
,
class
Class or The Class may refer to:
Common uses not otherwise categorized
* Class (biology), a taxonomic rank
* Class (knowledge representation), a collection of individuals or objects
* Class (philosophy), an analytical concept used differentl ...
Pinopsida
Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All extan ...
of the
division
Division or divider may refer to:
Mathematics
*Division (mathematics), the inverse of multiplication
*Division algorithm, a method for computing the result of mathematical division
Military
*Division (military), a formation typically consisting ...
Pinophyta
Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All extan ...
. The division includes all living
conifer
Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single ...
s. Recently however, some authorities treat Araucariaceae as a separate order, Araucariales.
Araucariaceae contains three extant
genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
and about 41 species.
Phylogeny
Below is the
phylogeny
A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...
of the Pinophyta based on
cladistic analysis
Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived chara ...
of molecular data. It shows the position of Araucariaceae within the division.
Relationships between living members of Araucariaceae.
Molecular evidence supports Araucariaceae and Podocarpaceae having diverged from each other during the late
Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...
.
Distribution and habitat
Today, 41 species are known, in three genera: ''
Agathis
''Agathis'', commonly known as kauri or dammara, is a genus of 22 species of evergreen tree. The genus is part of the ancient conifer family Araucariaceae, a group once widespread during the Jurassic and Cretaceous periods, but now largely re ...
'', ''
Araucaria'' and ''
Wollemia
''Wollemia'' is a genus of coniferous trees in the family Araucariaceae. It was known only through fossil records until 1994, when the Australian species ''Wollemia nobilis'' was discovered in a temperate rainforest wilderness area of the Wollemi ...
'', distributed largely in the
Southern Hemisphere.
By far the greatest diversity is in New Caledonia (18 species), with others in Australia, Argentina, New Zealand, Chile, southern Brazil, and
Malesia
Malesia is a biogeographical region straddling the Equator and the boundaries of the Indomalayan and Australasian realms, and also a phytogeographical floristic region in the Paleotropical Kingdom. It has been given different definitions. The ...
. In Malesia, ''Agathis'' extends a short distance into the
Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...
, reaching 18°N in the Philippines.
Uses
Several species are very popular ornamental trees in
garden
A garden is a planned space, usually outdoors, set aside for the cultivation, display, and enjoyment of plants and other forms of nature. The single feature identifying even the wildest wild garden is ''control''. The garden can incorporate bot ...
s in subtropical regions, and some are also very important
timber
Lumber is wood that has been processed into dimensional lumber, including beams and planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, wi ...
trees, producing
wood
Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin th ...
of high quality. Several have edible seeds similar to
pine nut
Pine nuts, also called piñón (), pinoli (), pignoli or chilgoza (), are the edible seeds of pines (family Pinaceae, genus ''Pinus''). According to the Food and Agriculture Organization, only 29 species provide edible nuts, while 20 are trad ...
s, and others produce valuable
resin
In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on natu ...
and
amber
Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In Ma ...
. In the
forest
A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...
s where they occur, they are usually dominant trees, often the largest species in the forest; the largest is ''Araucaria hunsteinii'', reported to 89 m tall in New Guinea, with several other species reaching 50–65 m tall. ''A. heterophylla'', the Norfolk Island pine, is a well-known landscaping and house plant from this taxon.
Skillful artisans in the Erzurum Province, Turkey, have used fossilized wood of Araucariaceae for centuries to manufacture jewelry and decorative items. It is known as "
Oltustone", the name deriving from the town of
Oltu
Oltu (; ) is a town and district of Erzurum Province in the Eastern Anatolia region of Turkey. The mayor is Necmettin Taşçı, from the AKP. The population was 31,087 in 2020.
History
An inscription found in Oltu’s castle has been dated to th ...
, where it is most commonly excavated. Despite the fact that this semiprecious gemstone is classified as “stone”, wood anatomy reveals it was fossilized pieces of trunks of Araucariacea. Oltustone, also called ‘Black Amber’ is unique to Turkey. It is dull and black, but when polished, acquires an attractive black sheen.
Fossil record
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
s widely believed to belong to Araucariaceae include the
form genera
Form classification is the classification of organisms based on their morphology, which does not necessarily reflect their biological relationships. Form classification, generally restricted to palaeontology, reflects uncertainty; the goal of s ...
''
Araucarites
''Araucarites'' is an extinct genus of conifer, used to refer to female conifer cones that resemble those of the family Araucariaceae. Species assigned to the genus lived in the Permian to Eocene
The Eocene ( ) Epoch is a geological epoch th ...
'' (various), ''
Agathoxylon
''Agathoxylon'' (previously known as ''Dadoxylon'') is a form genus of araucarian fossil wood, including massive tree trunks. Although identified from the late Palaeozoic to the end of the Mesozoic, ''Agathoxylon'' is common from the Carbonifero ...
'' and ''
Araucarioxylon
''Araucarioxylon arizonicum'' is an extinct species of conifer that is the state fossil of Arizona. The species is known from massive tree trunks that weather out of the Chinle Formation in desert badlands of northern Arizona and adjacent New Mex ...
'' (wood), ''
Brachyphyllum
''Brachyphyllum'' (meaning "short leaf") is a form genus of fossil coniferous plant foliage. Plants of the genus have been variously assigned to several different conifer groups including Araucariaceae and Cheirolepidiaceae. They are known from ...
'' (leaves), ''
Araucariacites'' and ''
Dilwynites'' (pollen), and ''
Protodammara'' (cones).
The oldest definitive records of Araucariaceae are from the
Early Jurassic
The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-J ...
, though there are potential earlier Late Triassic records. Early representatives of ''Araucaria'' are widespread across both hemispheres by the
Middle Jurassic
The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations co ...
, such as ''
Araucaria mirabilis
''Araucaria mirabilis'' is an extinct species of coniferous tree from Patagonia, Argentina. It belongs to the genus '' Araucaria''.
''A. mirabilis'' are known from large amounts of very well preserved silicified wood and cones from the Cerro ...
'' and ''
Araucaria sphaerocarpa
''Araucaria'' (; original pronunciation: .ɾawˈka. ɾja is a genus of evergreen coniferous trees in the family Araucariaceae. There are 20 extant species in New Caledonia (where 14 species are endemic, see New Caledonian ''Arauca ...
'' from the Middle Jurassic of Argentina and England respectively. The oldest records of the ''Wollemia''-''Agathis'' lineage from the
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
, including ''
Emwadea microcarpa'' from the
Albian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0.9 M ...
aged
Winton Formation
The Winton Formation is a Cretaceous geological formation in central-western Queensland, Australia. It is late Albian to early Turonian in age. The formation blankets large areas of central-western Queensland. It consists of sedimentary rocks suc ...
of Australia and ''
Wairarapaia mildenhallii'' from the Albian-
Cenomanian
The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...
of New Zealand.
The oldest fossils currently confidently assignable to ''Agathis'' are those of ''Agathis immortalis'' from the
Salamanca Formation
The Salamanca Formation is a geologic formation in the Golfo San Jorge Basin of central Patagonia that yields well-preserved, well-dated fossils from the early Paleocene. Studies of these fossils are providing new data on plant and animal diversit ...
of Patagonia, which dates to the
Paleocene
The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), E ...
, approximately 64.67–63.49 million years ago. ''Agathis''-like leaves are also known from the slightly older
Lefipán Formation
The Lefipán Formation is a Maastrichtian to Danian, straddling the Cretaceous-Paleogene boundary, geologic formation of the Cañadón Asfalto Basin in Chubut Province, Patagonia, Argentina. The up to thick stratigraphic unit comprises mudston ...
of the same region, which date to the very end of the Cretaceous.
See also
*
Paleobotany
Paleobotany, which is also spelled as palaeobotany, is the branch of botany dealing with the recovery and identification of plant remains from geological contexts, and their use for the biological reconstruction of past environments (paleogeogr ...
*
Te Matua Ngahere
Te Matua Ngahere is a giant kauri (''Agathis australis'') coniferous tree in the Waipoua Forest of Northland Region, New Zealand. The tree's Māori name means "Father of the Forest". Although not as massive or tall as its neighbour Tāne Mahuta, ...
References
Further reading
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{{Authority control
Pinales families
Extant Hettangian first appearances
Araucariales