Actinostrobus pyramidalis
Encyclopedia
Actinostrobus pyramidalis, commonly known as swamp cypress, is a species of coniferous tree
in the Cupressaceae
(cypress family). Like the other species in the genus, it is endemic
to southwestern Western Australia
.
Swamp cypress is a shrub
or small tree
, reaching eight metres tall. The leaves
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.
Actinostrobus pyramidalis was first collected from Perth in September 1841 by Johann Preiss, and a description was published by Friedrich Anton Wilhelm Miquel
in 1845. It is the type species
of its genus.
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...
in the Cupressaceae
Cupressaceae
The Cupressaceae or cypress family is a conifer family with worldwide distribution. The family includes 27 to 30 genera , which include the junipers and redwoods, with about 130-140 species in total. They are monoecious, subdioecious or dioecious trees and shrubs from 1-116 m tall...
(cypress family). Like the other species in the genus, it is endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
to southwestern Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
.
Swamp cypress is a 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...
or small 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...
, reaching eight metres tall. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are 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...
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
Conifer cone
A cone is an organ on plants in the division Pinophyta that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity...
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.
Actinostrobus pyramidalis was first collected from Perth in September 1841 by Johann Preiss, and a description was published by Friedrich Anton Wilhelm Miquel
Friedrich Anton Wilhelm Miquel
Friedrich Anton Wilhelm Miquel was a Dutch botanist.He was head of the botanical gardens at Rotterdam , Amsterdam and Utrecht . He directed the Rijksherbarium at Leiden from 1862...
in 1845. It is the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of its genus.