Thuja

Thuja is a genus of coniferous trees in the Cupressaceae (cypress family). There are five species in the genus, two native to North America and three native to eastern Asia. The genus is also known as arborvitae (from Latin for tree of life) due to the medicinal properties of the sap, bark, and twigs.

Description

Thuja species are evergreen trees growing from 10 to 200 feet (3 to 61 metres) tall, with stringy-textured reddish-brown bark. The shoots are flat, with side shoots only in a single plane. The leaves are scale-like 1–10 mm long, except young seedlings in their first year, which have needle-like leaves. The scale leaves are arranged in alternating decussate pairs in four rows along the twigs. Each leaf has a glandular pit at the base, which is often particularly noticeable on the leaf underside.

Species

The five species in the genus Thuja are:

• Thuja koraiensis – Korean thuja
• Thuja occidentalis – Eastern arborvitae, Northern whitecedar
• Thuja plicata – Western redcedar
• Thuja standishii – Japanese thuja
• Thuja sutchuenensis – Sichuan thuja

Uses

Thuja is widely used as an ornamental tree, particularly for screens and hedges, in gardens and parks. Its wood is used for roof shingles and for making small items such as boxes, fence posts, and musical instruments.

Medicinal use

The wood and leaves of Thuja contain thujone, a psychoactive substance that can cause hallucinations if ingested in large amounts. Thuja was used by Native Americans as a medicinal plant, a practice adopted by European settlers. It is also used in homeopathy and traditional Chinese medicine.

External links

• Gymnosperm Database: Thuja

Thuja Resources
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