Iron Dendrobium of Yandang Mountain

Iron Dendrobium of Yandang Mountain

Iron Dendrobium of Yandang Mountain is a product with a geographical indication for agricultural produce.

　　Yandang Mountain Dendrobium, commonly known as Wanzhangxu, is also called Yanshan Dendrobium. It is the foremost among China’s five famous types of Dendrobium and is a herbaceous plant of the Dendrobium genus in the Orchidaceae family. It is primarily produced within Yandang Mountain in Yueqing, southeastern Zhejiang Province, and mostly grows on damp, shaded rocks or moss-covered trees. Since Yueqing Dendrobium originates from the Yueqing region, it is named accordingly. Yueqing has been cultivating and producing Dendrobium since the Ming and Qing dynasties, with over 600 years of history in semi-wild cultivation. It has excellent medicinal efficacy and is a staple in traditional Chinese medicine pharmacies. Fresh Yueqing Dendrobium is about 10–35 cm long and about 0.5–0.8 cm in diameter. When processed into dried form, it becomes Yueqing Fāngdòu (Dendrobium stem twist), which is spiral-shaped with a diameter of about 0.7–1.2 cm and covered with a white film. There are many counterfeits in markets in other parts of China, often made without the white film and with wax coating, making them hard to distinguish.

　　Yandang Mountain Dendrobium is rich in polysaccharides, amino acids, and more than ten types of alkaloids such as dendrobine and nobilomine. According to identification by the Institute of Medicinal Plant Development under the Chinese Academy of Medical Sciences: the polysaccharide content is 12.745%, and the total alkaloid content is 0.029%. It can effectively enhance the body’s immune function and has special therapeutic effects on human organs such as the eyes, throat, lungs, stomach, intestines, and kidneys, as well as on blood and cardiovascular diseases. It can resist cataracts, delay aging, prevent mutations, and inhibit tumors (as stated in the Chinese Pharmaceutical Dictionary).

　　Quality Characteristics

　　1. External Sensory Characteristics: 1.1 Fresh Product: The stems are upright, iron-blue or purplish-green, cylindrical, 9–36 cm long, 3–9 mm in diameter, with distinct black nodes. The nodes are indented, the internodes slightly swollen, 1.3–1.7 cm long, and have a thick sticky texture when chewed. Leaves are arranged in two rows, papery, 6–10 in number, oblong-lanceolate or elliptical, 3.5–5.4 cm long and 0.9–1.5 cm wide. The upper surface of the leaves is green, while the lower surface is gray-green. The base of the leaves extends downward to form sheaths that embrace the stem. The leaf sheaths often have purple spots. The raceme usually emerges from the upper part of the old stem, bearing 2–5 flowers. The flowers are yellow-green, with red patches on the central part of the lip. 1.2 Dried Product: Iron Dendrobium Fāngdòu: Yellow-green or slightly golden. It has a faint fragrance, a mild taste that turns slightly sweet, sticky initially when chewed and then becomes viscous, with little to no residue. It is spiral or spring-shaped, typically with 2–5 twists. When straightened, the stem is 3.5–10 cm long and 0.2–0.3 cm in diameter, easily breakable with a flat cross-section. Iron Dendrobium Dry Stems: Gray-green or yellow-green, with a faint fragrance, a mild taste that turns slightly sweet, sticky initially and then viscous. The surface has fine longitudinal wrinkles and is firm in texture. 2. Internal Quality Indicators: 2.1 Fresh Product: Crude polysaccharides (calculated as glucose) ≥25% (after drying). 2.2 Dried Product (Iron Dendrobium Fāngdòu, Dry Stems): Iron Dendrobium polysaccharides (calculated as anhydrous glucose) ≥25%, mannose 13.0%–38.0%. 2.3 Safety Requirements: Comply with the Zhejiang Provincial Local Standard “Technical Regulations for the Production of Iron Dendrobium” (DB33/T635-2015).

　　The protected geographical indication area for Iron Dendrobium of Yandang Mountain includes areas from the east of Dajing Town in Yueqing City to Beibaixiang Town in the south, from Furong Town in the west to Zhiren Township in the north. The geographical coordinates are between 120°48′41″–121°15′15″ east longitude and 28°2′42″–28°32′18″ north latitude. It encompasses 342 administrative villages across 10 towns and 2 subdistricts, including Dajing Town, Zhiren Township, Huwu Town, Xianxi Town, Longxi Township, Yandang Town, Furong Town, Danxi Town, Lingdi Township, Beibaixiang Town, Chengjie Subdistrict, and Baishi Subdistrict in Yueqing City. The current planting base covers an area of 800 hectares, yielding 1,200 tons of fresh Iron Dendrobium stems and 400 tons of Iron Dendrobium Fāngdòu annually. The protected area spans 72,300 hectares.