Callitris pyramidalis, known variously as the Swamp Cypress, Swan River Cypress and King George’s Cypress, is a tall shrub or small tree said to reach a height of eight metres. In our cold climate garden specimens reach about four metres after five years in the ground. They tend to attain a greater height with more watering.
The typical Callitris foliage is dark green. The male cones are small, 3–6 mm long, and are found on the ends of the twigs. The female cones are globular to ovoid, 15 centimetres in diameter. Female cones are both profuse and conspicuous.
In common with other Callitris the cones, of this species, are held on the plant for many years. They only open if a branch or the tree dies. Because of the number of cones large numbers of seeds are released in the event of damage or death of the plant. As an example: A solitary C. pyramidalis, on a Western Australian island, was killed by fire. Subsequently hundreds of seedlings germinated. Up to 150 seedlings were counted per square meter ten metres from the deceased plant.
The Swamp Cypress is endemic to the southwest corner of Western Australia.
Callitris are excellent accent trees with their columnar form or in small groves.
Propagate from seed.
The species was collected, from Perth, in 1841 by Johann Preiss and named Actinostrobus pyramidalis. In 2010 the species was renamed Callitris pyramidalis.
The thumbnail is a watercolour painting, of a stem, by Robert Fitzgerald in the 1870’s.