Peilan is the name of a traditional Chinese medicine. It consists of the dried aerial parts of Eupatorium fortunei Turcz., a plant belonging to the genus Eupatorium in the Asteraceae family. It has the effects of dispelling dampness through its aromatic properties, invigorating the spleen and stimulating the appetite, and relieving surface symptoms caused by summer heat. It is primarily used to treat dampness obstructing the middle jiao, exterior syndromes caused by summer heat and dampness, and the early stages of damp-heat diseases.
Peilan
Peilan is the name of a traditional Chinese medicine. It consists of the dried aerial parts of Eupatorium fortunei Turcz., a plant belonging to the genus Eupatorium in the Asteraceae family. It has the effects of dispelling dampness through its aromatic properties, invigorating the spleen and stimulating the appetite, and relieving surface symptoms caused by summer heat. It is primarily used to treat dampness obstructing the middle jiao, exterior syndromes caused by summer heat and dampness, and the early stages of damp-heat diseases.
Chinese Name : 佩兰
Latin Name : Eupatorii Herba
Aliases : Lan, Lancao, Shuixiang, Duliangxiang, Dazelan, Lanze, Yanweixiang, Shuixiulan, Haierju, Qianjincao, Shengtoucao, Nulan
Authentic Producing Area : Mainly produced in Jiangsu, Zhejiang, Hebei, Shandong, and other regions.
Nature, Flavor & Meridian Tropism : Pungent in taste, neutral in nature; enters the Spleen, Stomach, and Lung meridians
Benefits & Efficacy
Benefits
Aromatic, dispels dampness; invigorates the spleen and stimulates the appetite; releases exterior pathogens and relieves summer heat.
Indications
Mainly used to treat dampness obstructing the middle jiao, exterior syndrome of summer-heat with dampness, and the early stages of damp-heat disease.
Usage and Dosage
Oral use: Decocted, 5–10 g. Double the dose for fresh herb.
Precautions
Use with caution in cases of yin deficiency with blood dryness or qi deficiency.
Chemical Constituents
The whole herb contains 0.5%–2% essential oil. The oil contains polyumbelliferone (p-isopropylbenzene) and nerol acetate; the leaves contain coumarin, o-coumaric acid, and muscari hydroquinone. It also contains triterpenoid compounds.
Pharmacological Actions
A decoction of Agastache rugosa exhibits inhibitory effects against Corynebacterium diphtheriae, Staphylococcus aureus, Streptococcus octodecatum, Proteus, and Salmonella typhi. Its essential oil, as well as the compounds umbelliferone and nerol acetate contained therein, exert direct inhibitory effects on influenza viruses. Agastache rugosa essential oil and its active constituents demonstrate significant expectorant effects when umbelliferone is administered via gastric lavage.
Relevant Discussions
1. *Shennong Bencao Jing*: “It promotes urination, neutralizes poisonous spells, and wards off misfortune. Long-term use boosts vital energy, lightens the body, prevents aging, and clarifies the mind.”
2. *Bencao Jing Shu*: “It stimulates the appetite and eliminates nausea, clears the lungs and resolves phlegm, and disperses stagnation.”
Applications
Clinical Applications
1. For treating conditions caused by dampness obstructing the middle jiao, it is often used in synergy with Agastache, and combined with Atractylodes, Magnolia bark, and Cardamom seeds to enhance its aromatic damp-resolving properties.
2. For treating spleen-damp-heat syndromes—such as a sweet, greasy taste in the mouth, excessive salivation, and bad breath—it can be used alone in a decoction, such as the Orchid Grass Decoction (*Su Wen*), or combined with herbs like Scutellaria baicalensis, Paeonia lactiflora, and Glycyrrhiza uralensis.
3. For treating summer-heat-dampness syndrome, it is often used in combination with Agastache, lotus leaf, and Artemisia annua. In the early stages of damp-heat syndrome, it can be used with talc, coix seed, and Agastache.
Related Compatibility
1. Agastache combined with Coptis: Agastache excels at invigorating the spleen, stimulating appetite, and resolving dampness; Coptis excels at clearing heat and drying dampness. When combined, their efficacy in clearing heat and resolving turbidity is greatly enhanced. This formula is suitable for symptoms of spleen-stomach dampness stagnation, such as chest tightness, indigestion, a bitter taste in the mouth, and a greasy tongue coating.
2. Agastache combined with Amomum: Agastache has a fragrant aroma and clears the lungs, stimulates the appetite, dispels dampness, and soothes the spleen; Amomum has a strong, pungent aroma and regulates qi, relieves epigastric fullness, dispels dampness, and stops vomiting. When combined, these two herbs work to dispel dampness with their aromatic properties, invigorate the spleen and stimulate the appetite, and descend rebellious qi to stop vomiting. This combination is suitable for conditions such as qi stagnation due to dampness obstruction, nausea and vomiting with loss of appetite, epigastric fullness, and a greasy tongue coating.
3. Agastache combined with Talc: Agastache invigorates the spleen and stimulates the appetite; Talc promotes diuresis and clears heat. When combined, these two herbs enhance their ability to relieve summer heat, invigorate the spleen, clear heat, and promote diuresis. This combination is suitable for summer heat syndromes.
4. Peilan combined with Mu Xiang: Peilan has a delicate, fragrant aroma that dispels dampness and stimulates the spleen and appetite; Mu Xiang has a strong, pungent aroma that relieves stagnation, promotes the flow of qi, and alleviates pain. When combined, these two herbs work to dispel dampness through their aromatic properties and promote the flow of qi to relieve pain. This combination is suitable for conditions such as epigastric fullness, abdominal distension, borborygmi, vomiting, and diarrhea caused by dampness-obstruction and qi stagnation.
5. Agastache combined with Lotus Leaf: Agastache relieves summer heat and dispels dampness; Lotus Leaf clears heat and relieves summer heat. When used together, these two herbs have a light and refreshing nature that promotes dispersion, demonstrating significant efficacy in clearing heat, relieving summer heat, and dispelling dampness. This combination is suitable for conditions such as fever, headache, epigastric fullness, and loss of appetite caused by internal accumulation of summer heat and dampness.
6. Agastache combined with Silverweed: Agastache has a pungent, aromatic scent that regulates qi, promotes diuresis, and removes dampness; Silverweed activates blood circulation, regulates qi, unblocks meridians, and promotes diuresis.When combined, these two herbs—one addressing Qi and the other addressing blood—use their aromatic properties to dispel turbidity, promote blood circulation, and eliminate water retention to reduce swelling. This combination is suitable for conditions such as dampness obstruction and blood stasis, edema and abdominal distension, difficulty urinating, and swelling and pain from external injuries.
7. Agastache combined with Acorus tatarinowii: Agastache has an aromatic quality that dispels turbidity, transforms dampness, harmonizes the middle burner, and stimulates the spleen to improve appetite;Acorus tatarinowii is aromatic, opens the orifices, warms and transforms dampness and turbidity, and harmonizes the middle jiao. When used together, these two herbs are highly effective at stimulating the appetite with their aromatic properties, regulating qi, and harmonizing the middle jiao. They are suitable for treating epigastric fullness, abdominal distension, vomiting, nausea, diarrhea, and costal pain with a greasy tongue coating caused by dampness obstructing the middle jiao and disharmony between the liver and stomach.
Medicinal Identification
1. Agastache and Agastache rugosa: Both Agastache and Agastache rugosa have a pungent taste and aromatic nature, primarily entering the Spleen and Stomach meridians. They are both capable of dispelling dampness through their aromatic properties, relieving summer-heat, and promoting sweating. They can be used to treat epigastric and abdominal distension, loss of appetite, nausea, and vomiting caused by dampness obstructing the middle jiao, as well as the early stages of summer-heat or damp-heat exogenous pathogens.as well as chills and fever, headache, epigastric fullness, nausea, vomiting, and diarrhea caused by external invasion of wind-cold or internal injury from raw and cold foods during the hot summer months. The two are often used in combination. However, Agastache is slightly warm in nature and dispels dampness without causing dryness or heat; its pungent action disperses the exterior without being overly harsh. It is a key herb for aromatically transforming damp turbidity, and its ability to resolve exterior syndromes is stronger than that of Agastache, making it more commonly used for exterior syndromes caused by external pathogens;Agastache also transforms dampness, harmonizes the middle burner, and stops vomiting; it is most suitable for nausea and vomiting caused by damp turbidity obstructing the middle burner. When combined with other herbs, it can also be used for cold, heat, or deficiency of the stomach, as well as pregnancy-related vomiting.Peilan, on the other hand, is neutral in nature and lacks the strength of Huoxiang in dispersing the exterior. Its strengths lie in transforming internal dampness, removing stagnant substances, and dispelling foul and turbid qi. It is used for damp-heat in the Spleen meridian, manifested by a sweet and greasy taste in the mouth, excessive salivation, foul breath, and a greasy, thick tongue coating.
2. Peilan and Xiangru: Both herbs possess aromatic properties that dispel dampness, relieve summer heat, and induce sweating. They are used to treat symptoms such as aversion to heat and a preference for cold drinks, epigastric and abdominal fullness, vomiting, diarrhea, and dysentery during the hot summer months, and are often combined to enhance their effects.However, Peilan has a neutral nature and excels at eliminating stagnant substances and dispelling foulness, making it an excellent herb for treating spleen dampness manifested as a sweet taste in the mouth and foul breath; Xiangru has a stronger ability to induce sweating and release the exterior, and it can also harmonize the middle burner, transform dampness, and promote urination.
Related Prescriptions
Lei’s Method of Aromatic Dampness-Resolution (from *Treatise on Seasonal Diseases*).
Medicinal Diet Therapy
Peilan Tea:
1. Benefits: Dispels turbidity with its aromatic properties and helps prevent the flu.
2. Ingredients: 30 grams each of fresh Agastache and fresh Peilan, and 6 grams of fresh peppermint leaves.
3. Preparation: Wash the ingredients, place them in a pot, add 3,500–4,000 milliliters of water, bring to a boil, and simmer for 3–5 minutes. (If using dried herbs, reduce the dosage by half.)
4. Usage: Drink frequently as a substitute for tea.
Notes
Patients requiring treatment with Chinese herbal medicine should first consult a licensed Traditional Chinese Medicine (TCM) hospital to receive a prescription following a professional TCM differential diagnosis.
Processing & Preparation
Harvesting & Processing
Harvest twice during the summer and fall seasons. Cut into sections for raw use, or use fresh.
Processing Methods
Take the raw herbal material, remove impurities, withered leaves, old stems, and residual roots; rinse quickly with water, moisten slightly, cut into sections, and sun-dry or dry at a low temperature.
Storage Methods
Store in a dry container in a cool, dry place to prevent mold.
Crude Drug Identification
Identification
1. Microscopic examination of the leaf surface: The vertical walls of the upper epidermal cells are slightly curved; those of the lower epidermal cells are wavy. Non-glandular trichomes are occasionally observed, consisting of 3–6 cells and reaching a length of up to 105 μm. Non-glandular trichomes on the leaf veins are relatively long, consisting of 7–8 cells and measuring 120–160 μm in length. Stomata are of the indeterminate type.
2. Take 1 g of the powdered sample, add 15 mL of petroleum ether (30–60 °C), sonicate for 10 minutes, filter, and evaporate the filtrate to dryness. Dissolve the residue in 1 mL of petroleum ether (30–60 °C) to prepare the test solution. Separately, take 1 g of the reference material (Perilla frutescens) and prepare the reference solution using the same method.Test by thin-layer chromatography (General Chapter 0502): Pipette 5 μl of each of the two solutions and apply them separately onto the same silica gel G plate. Develop with a mobile phase of petroleum ether (30–60 °C) and ethyl acetate (19:1), remove the plate, allow it to air-dry, spray with vanillin-sulfuric acid solution, and heat until the spots appear clearly.In the chromatogram of the test sample, spots of the same color appear at positions corresponding to those in the chromatogram of the reference herbal material.
Properties of Crude Drugs
The stem is cylindrical, 30–100 cm long, and 2–5 mm in diameter. The surface is yellowish-brown or yellowish-green, with distinct nodes and longitudinal ridges; internodes are 3–7 cm long. The stem is brittle; the pith is white or hollow when broken.Leaves are opposite, often shriveled and fragmented; when a complete leaf is flattened, it is usually 3-lobed, with lobes oblong or oblong-lanceolate, serrated margins, and a greenish-brown or dark green surface. It has an aromatic odor and a slightly bitter taste. Specimens that are tender, have many leaves, are green in color, and possess a strong aroma are considered superior.
Properties of Processed Slices
This product consists of irregular segments. The stem is cylindrical, with a yellowish-brown or yellowish-green surface, sometimes tinged with purple, and features distinct nodes and longitudinal ridges. The pith is white or hollow when cut. The leaves are opposite, mostly shriveled and fragmented, and greenish-brown. It has a fragrant aroma and a slightly bitter taste.
Botanical Information
Botanical Classification
Peilan, a plant of the genus Artemisia in the Asteraceae family.
Morphological Characteristics
A perennial herb, 40–100 cm tall. The rhizome is creeping. The stem is erect, green or reddish-purple, and smooth and glabrous at the base.Leaves are opposite; lower leaves are often withered; middle leaves have short petioles, with larger leaf blades that are usually trifurcated or deeply three-lobed, the central lobe being larger, oblong or oblong-lanceolate, 5–10 cm long and 1.5–2.5 cm wide;the upper leaves are smaller, often undivided, or all stem leaves may be undivided; the apex is acuminate, the margin coarsely toothed or irregularly finely toothed; both surfaces are glabrous or sparsely pubescent along the veins, without glandular dots. Numerous capitula are arranged in compound corymbs at the stem apex and branch tips, with an inflorescence diameter of 3–6 cm; the involucre is campanulate, 6–7 mm long;The involucral bracts are arranged in 2–3 layers in an imbricate pattern; the outer layer is short and ovate-lanceolate, while the middle and inner layers are progressively longer; all bracts are purplish-red, glabrous and without glandular dots on the outer surface, and blunt at the apex; each capitulum bears 4–6 flowers, which are white or slightly reddish, all tubular and bisexual, with corollas lacking glandular dots on the outer surface and 5-lobed at the apex;There are 5 stamens with fused anthers; the pistil is single, with an inferior ovary and a 2-lobed stigma that extends beyond the corolla. The achene is cylindrical, blackish-brown when ripe, 5-angled, 3–4 mm long, glabrous and without glandular dots; the pappus is white, approximately 5 mm long. Flowering and fruiting occur from July to November.
Distribution Area
Distributed in Hebei, Jiangsu, Zhejiang, Anhui, Jiangxi, Shandong, Hubei, Hunan, Guangdong, Guangxi, Sichuan, Guizhou, Yunnan, Shaanxi, and other regions.
Growth Habits
It prefers a warm and humid climate; it is cold-tolerant but sensitive to drought and waterlogging. Growth slows when temperatures fall below 19°C, but accelerates during seasons of high temperature and humidity. It is not particular about soil type, but grows best in loose, fertile, well-drained sandy loam.
Propagation Methods
Propagated by rhizomes.
Cultivation Techniques
Propagation by rhizomes: From November to March of the following year, dig up the rhizomes and select white, disease- and pest-free, plump, robust, fresh rhizomes with dense and evenly spaced nodes as planting stock. Dig furrows with a row spacing of 30 cm and a depth of 3–6 cm. Plant two rows, spacing the ends 3 cm apart. Cover with soil and lightly tamp down; seedlings will emerge in about 15 days.
Pest and Disease Control
1. Diseases include root rot; treat by pouring 5% lime water over the roots.
2. Pests include red spider mites, cabbage loopers, and leaf fleas.