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''Athrotaxis'' is a genus of two to three species (depending on taxonomic opinion) of
conifers 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 ...
in the cypress family,
Cupressaceae Cupressaceae is a conifer family, the cypress family, with worldwide distribution. The family includes 27–30 genera (17 monotypic), which include the junipers and redwoods, with about 130–140 species in total. They are monoecious, subdio ...
. The genus is
endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
to western
Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...
, where they grow in high altitude
temperate rainforest Temperate rainforests are coniferous or broadleaf forests that occur in the temperate zone and receive heavy rain. Temperate rain forests occur in oceanic moist regions around the world: the Pacific temperate rain forests of North American Paci ...
s.Farjon, A. (2005). ''Monograph of Cupressaceae and Sciadopitys''. Royal Botanic Gardens, Kew. Australian Plant Names Index
''Athrotaxis''
/ref> They are medium-sized
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 ...
tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...
s, reaching 10–30 m (rarely 40 m) tall and 1-1.5 m trunk diameter. The
leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
are scale-like, 3–14 mm long, are borne spirally on the shoots. The
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 ...
are globose to oval, 1–3 cm diameter, with 15-35 scales, each scale with 3-6
seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
s; they are mature in 7–9 months after pollination, when they open to release the seeds. The male (pollen) cones are small, and shed their pollen in early spring. They are very susceptible to
bush fire A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identif ...
s, and have declined markedly in abundance due to accidental and deliberate fires since the European colonisation of Tasmania.


Taxonomy

A 2021 molecular study found the Athrotaxidoideae to be the sister group to the
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 ...
, which contains famously massive species such as the
coast redwood ''Sequoia sempervirens'' ()''Sunset Western Garden Book,'' 1995:606–607 is the sole living species of the genus '' Sequoia'' in the cypress family Cupressaceae (formerly treated in Taxodiaceae). Common names include coast redwood, coastal ...
(''Sequoia sempervirens'') and
giant sequoia ''Sequoiadendron giganteum'' (giant sequoia; also known as giant redwood, Sierra redwood, Sierran redwood, California big tree, Wellingtonia or simply big treea nickname also used by John Muir) is the sole living species in the genus ''Sequoiade ...
(''Sequoiadendron giganteum''). This is despite both subfamilies' current distributions being on entirely different hemispheres. The study indicates that both taxa diverged during the mid to late
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 ...
.


Species

The three
taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...
of ''Athrotaxis'' are variously treated as three distinct species, or as two species, with the third taxon being a
hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...
between the other two. To date, the evidence has been inconclusive, with some data suggesting hybrid origin, but other evidence suggesting the third is distinct and not a hybrid.


Cultivation and uses

The
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 ...
is scented and durable, and was extensively used in the past in Tasmania, but is now too rare for any cutting. All three make very attractive
ornamental tree Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...
s with luxuriant foliage, though they are generally only planted in
arboretum An arboretum (plural: arboreta) in a general sense is a botanical collection composed exclusively of trees of a variety of species. Originally mostly created as a section in a larger garden or park for specimens of mostly non-local species, man ...
s or
botanical garden A botanical garden or botanic gardenThe terms ''botanic'' and ''botanical'' and ''garden'' or ''gardens'' are used more-or-less interchangeably, although the word ''botanic'' is generally reserved for the earlier, more traditional gardens, an ...
s. Cultivation away from their native range is successful only in areas with high rainfall, mild winters, and cool summers, such as the
British Isles The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...
, the
Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...
of
North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, and
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 ...
. Examples of the species and many of its leaf forms may be seen in the living collections at
The Tasmanian Arboretum The Tasmanian Arboretum is a botanical tree park (an arboretum) near Devonport, Tasmania, Australia. History The arboretum was incorporated on 16 May 1984. The site originally consisted of 47ha of farmland and remnant forest which was purchas ...
.


References

{{Taxonbar, from=Q1368777 Cupressaceae Pinales of Australia Flora of Tasmania Endemic flora of Tasmania Conifer genera