Chinese <I>Arbor-Vitae</i>

Chinese Arbor-Vitae

Chinese Arbor-Vitae
This genus of six species of evergreen coniferous trees occurs in E Asia and N America. Thuja occidentalis and T orientalis are widely grown as ornamentals; both have numerous cultivars, varying in size, habit and color, making them some of the most versatile conifers for garden use. Thujas have aromatic foliage, rich in volatile oil, which consists mainly of thujone, a toxic compound also found in Artemisia absinthium (See, Wormwood). Thuja occidentalis has long been used by native N Americans, providing materials for bows, canoes, baskets, cordage, and roofing, and medicines to treat menstrual problems, headache, and heart disease. It was made into anti-rheumatic tea by loggers in the wetland forests where it grows wild, and listed in the U.S. Pharmacopoeia (1882-94) as a uterine stimulant and diuretic. Thuja orientalis was first described in Chinese medicine in the Tang Materia Medica (c.CE569). Some botanists now classify this species as Platycladus orientalis.

Pyramidial shrub or conical small tre with red-brown, fibrous bark and vertical sprays of very samll, scale-like leaves, which usually turn bronze or brown in winter. Upright, gray-bloomed cones, 2cm (¾in) long, are flask-shaped.

Common Name:

Chinese Arbor-Vitae

Botanical Name:

Thuja orientalis syn. Biota orientalis, Platycladus orientalis

Genus:

Thuja

Family:

Cupressaceae

Native Location:

China and Iran

Cultivation:

Deep, moist, well-drained soil in sun. Dislikes cold, drying winds when young. Trim hedges in spring and late summer. Trees may be damaged by scale insects, aphids, canker, and Keithia disease.

Propagation:

By seed sown in late winter (species only); by semi-ripe cuttings in late summer.

Harvest:

Foliage and bark are removed as required and dried for use in decoctions, liquid extracts, and tinctures. Seeds (T. orientalis) are collected from ripe cones in autumn and dried for use in decoctions, powders, and tinctures.

Variants:

Aurea Nana
Is dwarf, with yellow-green foliage that bronzes in winter.
Height: 60cm (24in)
Width: 60cm (24in)

Height:

15m (50ft)

Width:

6m (20ft)

Hardiness:

Z5-9

Parts Used:

Foliage (ce bai ye), seeds (bai zi ren)

Properties:

A bitter, astringent, cooling herb that controls bleeding and coughing, stimulates the uterus, encourages hair growth, and is expectorant and anti-bacterial (foliage); a sweet, sedative, mildly laxative herb (seeds).

Medicinal Uses:

Internally for coughs, asthma, hemorrhage, excessive menstruation, bronchitis, skin infections, mumps, bacterial dysentery, arthritic pain, or premature baldness (foliage); and for palpitations, insomnia, nervous disorders, and constipation in the elderly (seeds).

Warning:

Preparations of leaves are contraindicated during pregnancy.
Leaves are toxic if eaten.
Skin allergen.

Bibliography: