Lawson's Cypress

A groovy purple stem

The Californian cypress grows into a large, pyramid shaped tree with pendent top shoots. The crown is narrow and conical. Mature specimens spread their branches so the tree appears wider. The bark is smooth, grey-brown and shiny but later turns purple in colour and forms grooves. As the tree matures the bark begins to flake. The scaly leaves are bright green and triangular and are attached to flattened, horizontally borne twigs, which together resemble a fern frond.

The male cones are club shaped and carmine red in colour. They can reach 5 mm in length and sit at the tips of the branches. The green, spherical female cones sit at the tips of short twigs and as they mature they become purple-brown and woody and contain the winged seeds.

Upwards of 70 m high

In the wild Lawson’s cypress grows along a narrow strip in the extreme north of California and in the south of Oregon. The cultivars of this species are popular garden plants, often planted as hedging. When rubbed the scale-like leaves smell of parsley. This conifer produces white, aromatic wood of high quality. The tallest specimen in America is more than 70 m high in Europe 40 m is the maximum. The wood is used both in shipbuilding and the furniture industry.

Ecology and habitat

In its natural habitat the Lawson’s cypress can be found growing from sea level up to an altitude of nearly 2000 m in the mountains. It grows in temperate rainforest where there is ample groundwater, particularly in the warm summer months, on a wide range of soil types along with other conifers such as the Douglas fir (Pseudotsuga menziesii). Many different species, such as Rhododendron en Vaccinium (bilberry) grow in the understorey of these conifer forests.

Threats

Chamaecyparis lawsoniana is heavily exploited and the international trade in commercial, valuable timber is placing great pressure on the last remaining populations in the wild. The biggest threat is actually Phytophtora lateralis, a root disease related to potato blight. In many areas Lawson’s cypress has been eliminated by this fatal disease. In order to retain Lawson’s cypress in the wild the root rot fungus needs to be contained.

Since the fungal spores requires damp conditions to spread, limitations on traffic movement during the wet season may be found to be effective. Researchers are also trying to cultivate a disease resistant strain of this cypress species.