''Athrotaxis'' is a genus of two to three species (depending on taxonomic opinion) of conifers in the cypress family, Cupressaceae. The genus is

endemic Endemism is the state of a species being found only 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 foun ...

to western

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

, where they grow in high-elevation

temperate rainforest Temperate rainforests are rainforests with coniferous or Broad-leaved tree, broadleaf forests that occur in the temperate zone and receive heavy rain. Temperate rainforests occur in oceanic moist regions around the world: the Pacific temperate ...

s.Farjon, A. (2005). ''Monograph of Cupressaceae and Sciadopitys''. Royal Botanic Gardens, Kew. They are medium-sized

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

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, e.g., including only woody plants with secondary growth, only ...

s, reaching 10–30 m (rarely 40 m) tall and 1-1.5 m trunk diameter. The

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

are scale-like, 3–14 mm long, are borne spirally on the shoots. The cones are globose to oval, 1–3 cm diameter, with 15-35 scales, each scale with 3-6

seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

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 fires, and have declined markedly in abundance due to accidental and deliberate fires since the European colonisation of Tasmania.

Classification

Taxonomy

''Athrotaxis'' is the only living genus of the subfamily Athrotaxidoideae. A 2021 molecular study found the Athrotaxidoideae to be the sister group to the

Sequoioideae Sequoioideae, commonly referred to as redwoods, is a subfamily of coniferous trees within the family Cupressaceae, that range in the northern hemisphere. It includes the largest and tallest trees in the world. The trees in the subfamily are ...

, which contains famously massive species such as the coast redwood (''Sequoia sempervirens'') and giant sequoia (''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 143.1 Mya. ...

. The oldest fossil of the genus is known from the Early Cretaceous (Aptian) of Santa Cruz Province in Argentina, South America, with other fossils of the genus known from New Zealand, eastern Australia, and possibly North America. Other fossils of the subfamily are known from the Late Jurassic of Europe, as well as the Early Cretaceous of North America and China, as well as possibly the Early Cretaceous of Europe, and Late Cretaceous of South America and North America.

Species

The three

taxa In biology, a taxon (back-formation from ''taxonomy''; : 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 name and ...

of ''Athrotaxis'' are variously treated as three distinct species, or as two species, with the third taxon being a hybrid between the other two. There is strong genetic evidence that the third taxon is a hybrid.

Cultivation and uses

The

wood Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin t ...

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 trees with luxuriant foliage, though they are generally only planted in

arboretum An arboretum (: arboreta) is a botanical collection composed exclusively of trees and shrubs of a variety of species. Originally mostly created as a section in a larger garden or park for specimens of mostly non-local species, many modern arbor ...

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. is ...

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 an archipelago in the Atlantic Ocean, 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 Hebrides, Inner and Outer Hebr ...

, the

Pacific Northwest The Pacific Northwest (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 no official boundary exists, the most common ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, and

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

. Examples of the species and many of its leaf forms may be seen in the living collections at The Tasmanian Arboretum.

References

{{Authority control Cupressaceae Pinales of Australia Endemic flora of Tasmania Conifer genera