Introduction of Xi Xin:Herba Asari or Asarum Root.
✵The TCM herbalism is also known as pharmaceutics of Traditional Chinese Medicine, or Chinese pharmaceutics, is the branch of health science dealing with the preparation, dispensing, and proper utilization of Chinese herbs. It is majorly composed of Introduction of Chinese Medicinals, Classification of Chinese Herbs, Formulas, and Patent medicines.
Classifications of Herbs:Pungent-Warm Exterior-releasing Herbs.
Introduction: Pungent-warm exterior-releasing herbs: an agent or substance herbs pungent in flavor and warm in property, which is usually used for treating a wind-cold exterior syndrome.
✵Till the date Oct 10th,2019, there are totally  kinds of common TCM herbs,  kinds of related plant species, are recorded in this category. These pungent-warm exterior-releasing Herbs are briefly introduced separately:
Herba Asari(Xi Xin or Asarum Root).
Pin Yin Name: Xì Xīn.
English Name: Asarum Root.
Latin Name: Herba Asari.
Property and flavor: warm, pungent, mild toxicity.
Brief introduction: The herb Herba Asari is the entire dried plant of Asarum heterotropoides var.manschuricum(Maxim.) Kitagawa, Asarum sieboldii Miq.var.seoulense Nakai(family Aristolochiaceae), used (1).to dispel wind and disperse cold for treating colds, (2).to relieve nasal congestion and alleviate pain for nasosinusitis, headache, toothache or rheumatic pain, and (3).to warm the lung and resolve retained fluid for treating cough with copious, thin expectoration. The herb is commonly known as Herba Asari, Asarum Root, Xì Xīn.
Botanical source: The herb Herba Asari(Xi Xin or Asarum Root) is the dried herb of the Asarum heterotropoides Fr. Schmidt var.mandshuricum（Maxim.）Kitag., it is a plant of the Aristolochiaceae family of the Aristolochiales order. It is also known as Manchurian Wildginger, Herb of Manchurian Wildginger, Herb of Seoul Wildginger, Herb of Siebold Wildginger.
Common official herbal classics and other famous herbal classics defined the herb Herba Asari(Xì Xīn or Asarum Root) as the dried herb of :(1).Asarum heterotropoides Fr. Schmidt var.mandshuricum（Maxim.）Kitag., (2).Asarum sieboldii Miq., (3).Asarum sieboldii Miq. var. seoulense Nakai. They are plants of the Asarum L. genus, the Aristolochiaceae family of the Aristolochiales order. These 3 commonly used species are introduced as:
(1).Asarum heterotropoides Fr. Schmidt var.mandshuricum（Maxim.）Kitag.: Botanical description: The plant is also known as Bei Xi Xin. Perennial herbs. The root goes sideways. Leaves are ovate-cordate or subreniform, 4~9 cm long, 5~13 cm wide, apex acute or obtuse, base cordate, upper veins hairy, sometimes all sparsely short-hairy, lower hairs dense; The bud leaves are nearly round. Flowers are purplish brown, thin purplish green; Pedicels 3~5 cm long, flowering at apical right Angle, fruiting erect; Perianth tube ampullate or hemispheric, ca. 1 cm in diameter, larynx slightly constricted, perianth lobes triangular-ovate, slices triangular-ovate, ca. 7 mm long, ca. 9 mm wide, reflexed outwardly from base, adherent to perianth tube. Stamens grow in the middle of the ovary, the filament is often slightly shorter than anthers, do not extend; Ovary semi-inferior or nearly epistatic, subglobose, 6 styles, apex 2-lobed, subcephalic. Capsule hemispherical, ca. 12 mm in diameter. Its flowering period is from May, fruiting from June to July.
Ecological environment: the plant grows on wet and fertile land under a forest slope or in a gully. It mainly distributes in the northwest and other areas of China.
Growth characteristics: The plant prefers cool and moist, avoid strong light and drought, bear cold, suitable to grow in shady slope, rich in humus loose and fertile soil, heavy soil and waterlogging land are not suitable for cultivation.
Characters of herbs: It often curls into a ball. The rhizome is irregular cylindrical, 1~10 cm long, 2~4 mm in diameter. The surface is gray-brown, rough, jointed, internode length 2~3 mm. Root is slender, dense nodes, 10~20 cm long, diameter about 1 mm; The surface is grayish-yellow; Brittle, easy to break, section yellow and white. Petiole of basal leaves is long, smooth, complete leaves flattened out and ovate-shaped or kidney-shaped, first rapids sharp or blunt, plug deep heart-shaped, 4~9 cm long, 5~13 cm wide, dark green surface, upper veins hairy, dense below. Flowers occasionally, purplish brown, hemispherical, perianth lobes reflexed from the base and attached to perianth tube. Smells aromatic, spicy taste, slightly tingle the tongue.
Pharmacological actions: ①.Antipyretic and analgesic effects: 0.2~1.0 ml/kg gum arabic emulsion of Asarum volatile oil was given orally to rabbits, which had a reduced effect on the fervescence(temperature rise) caused by normal and warm needling methods. ②.Bacteriostatic effect: Asarum has some inhibitory effects on Hemolytic streptococcus, Dysentery bacillus, Typhoid bacillus, and Tuberculosis bacillus in vitro. ③.Local anesthesia: Asarum infusion or ethanol infusion (20% ~ 100%) can block the impulse conduction of the frog sciatic nerve. In the guinea pig pimiosis test, it has an infiltrating anesthetic effect, but the decoction does not affect.
Medicinal efficacy: Dispelling wind and dissipating cold, relieve pain, warm lung and transform retention, free orifices, indicated for wind-cold headache, rhinitis, toothache, phlegm and retained fluid with cough, rheumatism pain or numbness.
Administration of Herba Asari(Xì Xīn):
Administration Guide of Herba Asari(Xì Xīn)
Internally:1~3 grams,Externally:proper amount(CP), or water decoction,0.3~1 qian(1~3 grams),Externally:grinded into fine powder,blow nose or mouthwash with water decoction(DCTM),or 1.5~9 grams, water decoction;grinded into fine powder,1~3 grams.Externally:proper amount, grinded into fine powder, blow to the nose or mouthwash with water decoction, or mouthwash with water decoction(CHMM).
(2).Asarum sieboldii Miq.: Botanical description: The plant is also known as Xi Xin, or Hua Xi Xin. Perennial herbs. Rhizome erect or transverse, internodes 1~2 cm long. Leaves usually 2, petiole 8~18 cm long; Bud leaf shape kidney round, margin sparsely pilose; Leaf blade cordate or ovate-cordate, 4~11 cm long, 4.5~13.5 cm wide, apex acuminate or acute, base deeply cordate, upper sparsely short-hairy, veins denser, lower veins hairy only. Flowers are purplish-black; Flowers are 2~4 cm long; Perianth tube bell-shaped, 1~1.5 cm in diameter, the inner wall with longitudinal ridge wrinkles. Perianth lobes triangular-ovate, erect or nearly spreading; Stamen bearing ovary middle, filaments and anthers subequal or slightly long, medicine room septum prominent, short conical; Ovary semi-inferior or nearly upper, globose, 6 flowers, shorter, apex 2-lobed, stigma lateral. Gourds nearly globose, about 1.5 cm in diameter. Its flowering period is from April to May.
Ecological environment: the plant grows in damp humus soil under the forest, it distributes in the lower reaches area of the Yangtze River, the middle reaches area of the Yellow River, northwest area, and other areas of China.
Characters of herbs: the herb is similar to Asarum heterotropoides Fr., but with slender rhizome, 5~15 cm long, 1~3 mm in diameter and 0.2~1 cm in internode length; Leaves are thinner, cordate. The smell is weak.
(3).Asarum sieboldii Miq. var. seoulense Nakai.: Botanical description: The plant is also known as Han Cheng Xi Xin. This variant is similar to Asarum, but leaf blade abaxially densely short hair, the petiole is sparse hair, can be distinguished.
Ecological environment: the plant grows under the forest, and in the damp valley, it distributes in the forest of north China.
Characters of herbs: the herb is very similar to Asarum sieboldii Miq., but usually the back of the leaf is hairier, petiole hairy. The hair density of cultivated leaves varies greatly and is not easy to be distinguished from Asarum sieboldii Miq.
1.Introduction of Xi Xin:Herba Asari or Asarum Root.
2.TCM Books:DCTM(Dictionary of the Chinese Traditional Medicine),CHMM(Chinese Herbal Materia Medica).