Sang Zhi

Botanical name: Morus alba
Common name: Mulberry twig, Morus twig

Family: Moraceae, mulberry family
Part used in Chinese medicine:  twig

Major Chinese medicine actions:
Dispels wind-dampness, unblocks channels and collaterals,
benefits joints

Sang Zhi

Sang Zhi

Sang Zhi

Sang Zhi
Photo Credits: (top to bottom)
Photo 1: Morus alba; 07/2008; author C. Micleu; permission Jade Institute
Photo 2: Morus alba; 07/2008; author C. Micleu; permission Jade Institute
Photo 3: Morus alba; 06/2005; author Luis Fernandez Garcia; permission under GFDL
Photo 4: Morus alba; 09/2006; author B.Navez; permission under GFDL

Comments:
Morus alba, or White Mulberry, is a short-lived, small to medium sized tree that can reach 30 to 50 feet in height. It is native to northern China where its cultivation for silkworm feedstock began over 4,000 years ago, and it is now cultivated and naturalized around the world in warm temperate regions. It is quite vigorous and fast growing, often seen in abandoned areas and roadsides. Recently it has been listed as an invasive plant in parts of North America as it tends to hybridize with the native Red Mulberry and threatens its long-term genetic viability.

The White Mulberry is scientifically notable for its rapid pollen release movement. The flowers fire pollen into the air by rapidly releasing stored elastic energy in the stamens, with a resulting movement that occurs at more than of half the speed of sound. It has the distinguished characteristic of making the fastest known movement in the plant kingdom.

In Chinese medicine, various parts of the White Mulberry are used. The leaves (Sang Ye), root bark (Sang Bai Pi), twigs (Sang Zhi), and dried fruit (Sang Shen) are all used medicinally.

Growing and Propagation

The tree grows in almost any soil and is somewhat drought tolerant, though prefers warm, well-drained, loamy soil in an environment with full sun. Mulberry roots are known for being brittle and require care when planting. On young trees, the leaves are quite large, up to one foot long, while on older trees they are only 2-6 inches long. The tree is usually deciduous in winter, but those grown in tropical regions can be evergreen. Pruning should be done sparingly and ideally only on dead wood, and only performed in the winter when the plant is fully dormant as mulberries bleed badly when cut.

Propagation is by seed or cuttings. Seed is best sown as soon as ripe if possible, otherwise in February in a cold frame. It will usually germinate in the first spring, though it sometimes takes another 12 months. When seedlings are large enough to handle they can be planted in pots and grown in a cold frame for their first winter, and planted in the ground in late spring or early summer after the last frost. Cuttings of half-ripe wood, can be taken in July-August, grown in a frame and planted out in the spring.

Harvesting and Preparation
Mulberry twigs are harvested in late spring or early summer. The leaves are removed, and after drying the twigs are cut into pieces. Good quality Sang Zhi consists of thin, tender twigs without leaves.