Globally it has many different species, in which the most common ones are cirsium vulgare, cirsium arvense, cirsium horridulum, and more. However none of the above-mentioned species is used for medicinal purpose. In TCM, it mainly refers to the dried aerial parts or roots of Cirsium japonicum DC. in the family Asteraceae. But sometimes a few other plants in the same genus are also considered as medicinal herbs. They are Cirsium maackii Maxim. [C. japonicum DC. Var. Maackii (Maxim.) Nakai]., Cirsium spicatum Matsum, Cirsium pendulum Fisch., Cirsium chlorolepis Petrak, Cirsium eriophoroideum (Hook. f.) Petrak, Carduus crispus L., and Carduus nutans L. However, now we are going to focus on the cirsium japonicum here since it is the most common used one.

Also known as Japanese thistle herb and Herba seu Radix Cirsii Japonici in Latin, this is a perennial herb, 0.5 to 1m high. Root is in clusters, conical, fleshy and with tan surface. Stems are erect, with thin vertical stripes and white silky hairs at base. Basal leaves are clustered, stalked, oblanceolate or obovate-lanceolate, 15 to 30cm in length, pinnatifid, with dentate edge. Since it features its effusive flower heads, the inflorescence is terminal capitulum. Achenes are oblong, with multilayered pappus, pinnate, and in the dark gray color. It blossoms from May to August and fruits from June to August.

MODERN PHARMACOLOGY 
1. Antibacterial effect. Root decoction or the whole plant extract, at the concentration of 1:4,000, can in vitro inhibit the growth of human toxic Mycobacterium tuberculosis. And alcohol infusions, at the concentration of 1:3,000, begin to inhibit human Mycobacterium tuberculosis. As demonstrated here the inhibitory concentration of water decoction is higher than that of alcohol infusion.

2. Effect on blood pressure. Water extract, ethanol-water extract and ethanol extract can lower blood pressure when used in anesthetized animals like dogs, cats, and rabbits. Cirsium can inhibit heart rate and cardiac contractility in isolated frog heart and rabbit heart. It also reduces dogs' blood pressure, has Tachyphylaxis, and inhibit BOC pressor reflex. All the evidences showed that Cirsium's antihypertensive effect and inhibition of heart rate are closely related to the inhibition of cardiac contractility.

3. Hemostatic effects. Animal experiments showed that it promotes the first stage of clotting process, namely the formation of prothrombin activator. As a result, this herb is ideal choice for the blood-heat bleeding, such as Hematemesis, Epistaxis, metrorrhagia and metrostaxis, Hematuria, etc. This herb can be used alone or combine with other hemostatic herbs.

POPULAR CIRSIUM RELATED CHINESE HERBAL FORMULAS
Traditional Chinese medicine (TCM) holds that this herb is sweet, bitter and cool in properties. It covers two meridains, including heart and liver. Its key functions are to cool and stop bleeding and eliminate stasis to subdue swelling. Basic cirsium uses and indications are epistaxis, hemoptysis, hematemesis, hematuria, functional uterine bleeding, postpartum hemorrhage, Hepatitis, Nephritis, Mastitis, and traumatic injury. External uses include traumatic bleeding, carbuncle, boils, and pyogenic infections. Usual dosage is from 5 to 10 grams and the dosage of fresh plant can be up to 60 grams.

Cirsium

1. Get juice by smashing and twisting fresh Cirsium thistles leaves and root. Take it in small doses at short intervals to treat spitting blood and dry mouth. – From Tai ping sheng hui fang (Taiping Holy Prescriptions for Universal Relief)

2. Squeeze juice from a handful of fresh herb. Take half liter of the juice for treatment of hematemesis, epistaxis, and metrorrhagia. – From Ben Cao Hui Yan (Treasury of Words on the Materia Medica)

3. Clean and smash 3 to 10 grams of fresh roots. Pour in due amount of boiled water and stew for one hour. Take it before the dinner and three times a day to treat coughing up blood due to lung heat. From Fu Jian Min Jian Cao Yao (Folk Herbs In Fujian)

4. Treat metrorrhagia and metrostaxis by the herbal formula of Da Ji, Ai Ye (Mugwort Leaf), Bai Ji Guan Hua Zi (Semen Celosiae.), Mu Er (Wood ear), and Chao Huang Bai (Dry Fried Amur Cork Tree Bark). – From Dian Nan Ben Cao (Pharmaceutical Natural History of Southern Yunnan)

5. Cure pulmonary abscess with decoction of 12 grams fresh Cirsium thistles. Take it before dinner and three times a day. – From Min Dong Ben Cao (East Fujian Materia Medica)