Cypress, Lawson (Chamaecyparis lawsoniana)
Lawson cypress is a dioecious evergreen tree native to California. It was introduced to Britain in 1854. There are now many ornamental cultivars.
Common name: Lawson cypress
Scientific name: Chamaecyparis lawsoniana
UK provenance: non-native
Interesting fact: the foliage has a pungent scent, rather like parsley.
What does Lawson cypress look like?
Overview: a narrowly conical tree that can reach up to 45m high. The trunk often forks. The bark is cracked into vertical plates and the twigs are a dark bluish-grey.
Leaves: short scale-like leaves are grouped in fours and hide the twigs, forming flat planes. They are closely pressed together producing flat sprays of foliage. They are green with a whitish tinge underneath.
Flowers: minute flowers, which look like buds, open at the twig tips in spring. Male flowers are crimson, becoming yellow with pollen, and females are blue.
Fruits: cones ripen from female flowers, starting green, then turning cream and finally ending brown. They are pea-sized with broad scales.
Look out for: the leaf scales, on flattened shoots, are fern-like and have narrow white markings underneath.
Could be confused with: true cypresses (Cupressus x leylandii). Lawson cypress twigs grow in flattened horizontal sprays. Cones are rarely more than 1cm in diameter and many cultivated varieties have golden or green-blue foliage.
Identified in winter by: the top of the tree droops over. The crushed foliage gives off a pungent smell a little like parsley.
Where to find Lawson cypress
This evergreen tree is grown widely in parks, gardens and churchyards. It can regenerate from seed, and has naturalised on banks, walls and woodland margins throughout lowland UK. It grows best in moist but not waterlogged soils.
Value to wildlife
The dense foliage provides shelter for nesting birds, including various finches, when many broadleaved trees are still in bud.
How we use Lawson cypress
In its native northern California, the Karuk people used Lawson cypress branches as brooms, and the wood as posts to build sweatlodges.
The wood, which is strong and light is highly valued in Japan for coffin and shrine construction. It is also used to make arrow shafts and musical instruments, especially guitars.
It is grown widely in the UK as an ornamental tree.
Particularly susceptible to Phytophthora root rot which causes branch dieback and wilting foliage.