Since the main medicinal part of costus is the root, medicinally it refers to the dried root of Saussurea costus (Falc.) Lipsch. (Aucklandia lappa Decne.), a plant of the genus Saussurea in the family Asteraceae. By the way, another medicinal plant called Chuan Mu Xiang or Vladimiria souliei (Franch.) Ling has the similar medicinal properties. And TCM physicians call both species Mu Xiang and believe that they are with only minor differences on medicinal properties. And other names of this herb include putchock, Yun Mu Xiang, kushta, Radix Aucklandiae, Qing Mu Xiang, puchuk, radix saussureae lappae, koshet, costusroot, kuth, costus root, kut Aucklandia Root, koot, Guag Mu Xing, and so on.

Costus plant is a perennial herb, 1.5 to 2 meter in height. Principal root is large. Stems are sparsely pubescent. Cauline leaves are with long handle; blade is triangular-ovate or in the shape of long triangle, 30 to 100cm long, 15 to 30cm wide, and with cordate base. Capitulum is acrogenous and axillary, about 3cm in diameter; a few costus flowers often aggregate on the top of the stalk; phyllary is with about 10 layers; corolla is dark purple, 5-lobed; stamens are 5; inferior ovary has style that outstretches corolla. Achene is in the shape of long taper and with two layers of feathery pappus at the top. Bloom time is from July to August and the fruit time is from August to October. The habitats are alpine meadows and bushwood at an altitude of above 2500m. In mainland China it is mainly produced in Sichuan, Yunnan, and Tibet. So far all of them are wild growing plants and not yet introduced by the artificial cultivation.

COSTUS BENEFITS
The costus health benefits has been known for thousands of years and it was first mentioned in Shen Nong Ben Cao Jing (The Divine Farmer's Materia Medica), which is the earliest material medical extant in China. Today, it is extensively used for many conditions. The single herb is often used to treat anicteric hepatitis and chronic persistent hepatitis. And costus-based formulas treat cholecystitis, infantile enteritis, bacillary dysentery, colic, flatulence, Peptic Ulcer, Diarrhea Predominant Irritable Bowel Syndrome (IBS-D), and dysmenorrhea. Here are some examples.

Costus

(1). 34 cases of chronic atrophic gastritis were ever treated with the combination of costus root, Chai Hu (Bupleurum), Gua Lou Ren (Semen Trichosanthis), Ban Xia (Pinellia), Zhi Ke (Fructus Aurantii), etc. And the total effective rate was 94%.

(2). 96 cases of acute diarrhea were treated with Xiang Shen Zhi Xie Fang, which is the Combination of costus and Ku Shen (Sophora Flavescens). And the result showed that the total effective rate was 97.9%;

(3). Cholelithiasis was ever treated with the decoction consisting of Yin Chen Hao (Herba Artemisiae Scopariae), Jin Qian Cao (Gold Coin Grass), costus, Bupleurum, Fructus Aurantii, etc. And discharge rate for stones was more than 60%;

SAMPLE COSTUS ROOT HERBAL REMEDIES 
1. Mu Xiang Wan from Tai Ping Sheng Hui Fang (Taiping Holy Prescriptions for Universal Relief). It is matched with Fructus Aurantii, Rhubarb, Qian Niu Zi (Morning Glory Seed), and He Li Le Pi (Terminalia Chebula Peel) to treat fullness and distention in abdomen and flanks and sticky stool due to the attack from Chi.

2. Mu Xiang Bing Lang Wan from Ru Men Shi Qin (Confucians' Duties to Serve Their Parents). It is used with Bing Lang (Betel Nut), Chen Pi (Citrus Peel), Huang Lian (Coptis Root), Xiang Fu Zi (Cyperus rotundus rhizome), etc. to cure aggradational body fluid and Chi, stabbing pain in flanks, failure to eat due to flatulence, and dizziness.

3. Da Xiang Lian Wan from Tai Ping Hui Min He Ji Ju Fang (Formulas of the Peaceful Benevolent Dispensary). It is couple with Coptis (Fried with cornel) to heal damp-heat diarrhea and tenesmus.