''Actinostrobus pyramidalis'', commonly known as swamp cypress, Swan River cypress and King George's cypress pine,Eckenwalder, J.E. 2009. ''Conifers of the World: The Complete Reference''. Timber Press. p. 124 is a species of

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 ...

ous tree in the

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 ...

(cypress family). Like the other species in the genus ''Actinostrobus'', it is endemic to southwestern Western Australia. Swamp cypress is a

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

or small tree, reaching eight metres tall. 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 evergreen and scale-like, except on young seedlings, where they are needle-like. The leaves are arranged in six rows along the twigs, in alternating whorls of three. The male cones are small, 3–6 mm long, and are located at the tips of the twigs. The female cones start out similarly inconspicuous, but mature in 18–20 months to 1–2 cm with a rounded apex. The cones open and release the seeds only upon drying. They tend to remain closed on the trees for many years, opening only if the branch, or the whole tree, dies. Bushfire kills swamp cypress, but it also causes a great many seeds to be released all at once, resulting in prolific regeneration. In one case, an isolated tree on Jeegarnyeejip Island was killed by fire, and the following winter there were 800 seedlings per square metre within a couple of metres of the original specimen, and about 150 per square metre ten metres away. The species was first collected from Perth in September 1841 by Johann August Ludwig Preiss, and a description was published by

Friedrich Anton Wilhelm Miquel Friedrich Anton Wilhelm Miquel (24 October 1811 – 23 January 1871) was a Dutch botanist, whose main focus of study was on the flora of the Dutch East Indies. Early life Miquel was born in Neuenhaus and studied medicine at the University of Groni ...

in 1845 as ''Actinostrobus pyramidalis''. A 2010 study of the genera ''Actinostrobus'' and ''Callitris'' found that all three species of ''Actinostrobus'' lay within the current concept of ''Callitris'' based on analysis of 42 morphological and anatomical characters, hence ''Actinostrobus pyramidalis'' was renamed ''Callitris pyramidalis''.Piggin, J., and Bruhl, J.J. (2010)

Phylogeny reconstruction of ''Callitris'' Vent. (Cupressaceae) and its allies leads to inclusion of ''Actinostrobus'' within ''Callitris''. ''Australian Systematic Botany'' 23: 69-93.

References

* * *Farjon, A. (2005). ''Monograph of Cupressaceae and Sciadopitys''. Royal Botanic Gardens, Kew. . *

External links

{{Taxonbar, from=Q2688669 pyramidalis Flora of Western Australia Pinales of Australia Near threatened flora of Australia Taxobox binomials not recognized by IUCN