Shi Hu

Botanical name: Dendrobium nobile
Common name: Dendrobium
Literal name translation: bushel of stone

Family: Orchidaceae, orchid family
Part used in Chinese medicine:  whole plant

Major Chinese medicine actions:
Nourishes Stomach and Kidney yin, clears heat from deficiency,
generates fluids, tonifies essence

Shi Hu

Shi Hu

Shi Hu

Photo Credits: (top to bottom)
Photo 2: Dendrobium nobile; 09/2008; author Guerin Nicolas: permission under GFDL
Photo 3: Dendrobium nobile hybrid; 11/2005; author Density; permission under GFDL

Comments:
The “noble” Dendrobium genus should not be confused with the warmer growing Dendrobium phalaenopsis types that are found in many stores. The D. phalaenopsis types have long branching flowering inflorescence and the D. nobile types produce their flowers attached to the canes.

These dendrobiums are native to Southeast Asia and grow in their native habitat on branches of tall trees in cool areas of high elevation in countries such as India, Burma, and Thailand. They are extremely hardy plants growing in elevations up to 3,000 feet where temperatures may drop to almost freezing. If kept dry, these species and hybrids will survive winter temperatures of 37-39 F and will flower around April. If temperatures are stay at about 62-64 F when buds appear, they will flower in January or February.

Growing and Propagation

Nobile dendrobiums are some of the easiest orchids to grow but can be difficult to induce regular blooms. Their flowers are very fragrant, with showy colors ranging from white through pink to purple, and the lip is often beautifully marked in contrasting colors. The plants need plenty of light and good air circulation, provided in their native habitat by breezes through tree branches. They require a cool winter dry rest in order to flower and if they do not receive sufficient cold during the winter they will produce keikis instead of flowers.

Plants can grow in semi-shade or full sun and requires moist soil. Direct filtered sunlight is essential for flowering, but they will do best when provided with 30-70% shade during midday. Bright light will generally encourage flowering, provided excessive leaf temperatures are avoided.

When cultivating dendrobiums indoors, the potting medium should be thoroughly soaked, and allowed to dry out before watering again. Watering twice a week is generally adequate with properly potted plants in most climates. With the change of the day-length and cooler night temperatures of the coming winter, the leaves turn yellow and fall off and when winter arrives they will be in a complete dormant condition.

From November to February the plants should be kept dry or given only a light spraying. Light and good air circulation should be provided. By spring the plants will look very neglected with shriveled pseudobulbs and no leaves, but signs of growth activity will begin and from March to August new leaves emerge, then roots and flowers appear.

Plants can be propagated by seed sown as soon as it is ripe. The seed of this species has a small embryo surrounded by a single layer of protective cells. It contains very little food reserves and depends upon a symbiotic relationship with a species of soil-dwelling fungus. The fungal hyphae invade the seed and enter the cells of the embryo. The orchid soon begins to digest the fungal tissue and this acts as a food supply for the plant until it is able to obtain nutrients from decaying material in the soil.

Harvesting and Preparation

Dendrobium is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES). It is not considered to be threatened with extinction at this time but trade is closely controlled in order to protect it. It may be possible to obtain this herb but plant ethics suggest it is best to use a substitute for medicinal use. The most common substitution for this herb is Ephemerantha fimbriata, which has very similar attributes and functions.