Dioscorea polystachya

Botanical Overview

Dioscorea polystachya, commonly called Chinese yam or Huai Shan, belongs to the Dioscoreaceae family. Native to East Asia including China, Korea, and Japan, this species is prized for its edible tuber and rhizomes, which are used medicinally. The plant is cultivated for its nutritive and therapeutic rhizomes.

Energetics

This herb is characterized as neutral in temperature and moistening in quality, with a sweet taste. It exhibits a descending directionality and is considered tonifying, supporting qi, essence, and bodily fluids in Traditional Chinese Medicine.

Primary Actions

  • Nutritive
  • Demulcent
  • Anti-inflammatory
  • Adaptogen

Indications

Western

  • Poor digestion
  • Diarrhea
  • Fatigue
  • Loss of appetite
  • Frequent urination
  • Menstrual irregularities

Syndromes

  • Malnutrition
  • Digestive weakness
  • Diabetes mellitus adjunct
  • Chronic inflammation

TCM

  • Spleen qi deficiency
  • Lung yin deficiency
  • Chronic cough
  • Spontaneous sweating
  • Night sweats
  • Lower back ache

Syndromes

  • Spleen and Lung qi deficiency
  • Yin deficiency with dryness
  • Chronic diarrhea
  • Kidney deficiency

Ayurveda

No well-supported traditional uses documented.

Unani

No well-supported traditional uses documented.

Constituents & Mechanisms

The primary phytochemicals include diosgenin (a steroidal sapogenin), starches, polysaccharides, steroid saponins, and allantoin, contributing to its nutritive, demulcent, and anti-inflammatory properties.

Dosage & Preparations

  • Decoction of rhizome 9-15 g, 1-2 times daily
  • Powdered rhizome 3-9 g daily
  • Tincture standardized to diosgenin content, dose variable

Safety & Contraindications

Generally regarded as safe in customary doses; however, pregnant women should exercise caution due to limited clinical safety data. Mild gastrointestinal discomfort may occur in sensitive individuals.

Astrological Correspondences

No reliable planetary or elemental attributions found in surveyed credible sources.

Selected References

  • Dioscorea polystachya – PFAF
  • Chinese Herbal Medicine Materia Medica, 3rd Edition
  • Pharmacopoeia of the People’s Republic of China, 2020 Edition