大通，行水
苦寒有毒（诸家辛酸，时珍苦寒）。沉阴下行，与大戟、甘遂同功。
疗水肿胀满（肿属脾，胀属肝。肿则阳气犹行，如单胀而不肿者名臌胀，为木横克土，
难治。肿胀朝宽暮急为血虚，朝暮俱急为气血两虚。肿胀由心腹而散四肢者吉，由四肢而入
心腹者危。男自下而上，女自上而下，皆难治）。瘕疝痈肿。喉痹不通，（薄切醋炒，涂喉中
良），湿热也病。泻蛊毒，敷恶疮，堕胎孕，令人见鬼神。
取花白者根（赤者伤人，只堪贴脐，入麝三分捣贴，小便利则，肿消），黑豆汤浸蒸用。
得蒜良。
大通，行水
苦寒有毒。去水饮痰癖。
疗五水在五脏、皮肤，胀满喘急，痛引胸胁，咳嗽瘴疟（五水者，风水、皮水、正水、
石水、黄汗也。水积胸中，坚满如石，名石水。汗如柏汁，名黄汗，久不愈必致痈脓。时珍
曰∶仲景治伤寒太阳证，表未解，心下有水而咳，干呕发热，或喘或利者，小青龙汤主之。
表已解，有时头痛，汗出恶寒，心下有水，干呕，痛引两胁，或喘或嗽者，十枣汤主之。盖
青龙散表邪，使水从汗出，《内经》所谓开鬼门也；十枣逐里邪，使水从两便出，《内经》
所谓洁净府、去陈 法也。十枣汤∶芫花、甘遂、大戟等分，枣十枚）。
叶似柳，二月开花紫碧色，叶生花落。陈久者良。醋煮过，水浸曝用。根疗疥，可毒鱼
。反甘草（斗讼者，取叶擦皮肤，辄作赤肿，假伤以诬人）。
大通（商陆的别名），具有通利水道、行气消肿的功效。
味苦，性寒，有毒。（历代医家多认为其味辛或酸，李时珍认为其味苦性寒）。
药性沉降，主下行，与大戟、甘遂功效相同。
治疗水肿胀满（肿胀属于脾病，胀满属于肝病。肿证阳气尚能运行，若只有胀满而无浮肿者称为鼓胀，为肝木横逆克制脾土，难以治疗。肿胀早晨缓解傍晚加重为血虚，早晚都加重为气血两虚。肿胀从心腹部向四肢消散者为吉兆，从四肢向心腹部蔓延者为危症。男性病变自下而上发展，女性病变自上而下发展，都属于难治之症）。
治疗癥瘕、疝气、痈肿。
治疗喉痹不通（将药薄切后用醋炒制，涂抹于喉中效果良好），以及湿热邪气引起的疾病。
泻除蛊毒，敷贴恶疮，堕胎，令人产生幻觉看见鬼神。
取白色的花和根部（红色的会伤害人体，只能用于贴敷脐部，加入三分麝香捣碎后贴敷，小便通畅则肿胀消退），用黑豆汤浸泡蒸熟后使用。
与大蒜同用效果良好。
大通（芫花的别名），具有行水、祛除水饮痰癖的功效。
治疗五脏及皮肤中的五种水气病，表现为胀满、喘急，疼痛牵引胸胁，咳嗽、瘴疟（所谓五水，是指风水、皮水、正水、石水、黄汗。水积聚在胸中，坚硬胀满如石头，称为石水。汗液颜色如柏树汁，称为黄汗，久治不愈必然导致痈脓。李时珍说：张仲景治疗伤寒太阳证，表证未解，心下有停水而咳嗽，干呕发热，或者气喘或者腹泻的，用小青龙汤主治。表证已解，有时头痛，出汗怕冷，心下有停水，干呕，疼痛牵引两胁，或者气喘或者咳嗽的，用十枣汤主治。大概小青龙汤是发散表邪，使水气从汗液排出，《内经》所说的“开鬼门”；十枣汤是攻逐里邪，使水气从大小便排出，《内经》所说的“洁净府、去陈莝”。十枣汤由芫花、甘遂、大戟等分组成，大枣十枚）。
叶子像柳树，二月开出紫碧色的花，先长叶后开花。存放时间久的药材质量较好。用醋煮过，用水浸泡晒干后使用。根部治疗疥癣，可以用来毒杀鱼。
反甘草（争斗诉讼的人，取叶子擦拭皮肤，立即出现红肿，假装受伤来诬陷他人）。
Datong (alias for Phytolaccae Radix), promotes water metabolism and moves qi to reduce swelling.
Bitter, cold, toxic. (Previous authorities considered it acrid or sour; Li Shizhen considered it bitter and cold).
The nature is heavy and descending, acting on the lower part, with effects similar to Euphorbiae Pekinensis Radix (Daji) and Kansui Radix (Gansui).
Treats edema and distension (Swelling belongs to Spleen disorders, distension belongs to Liver disorders. In swelling, yang qi still circulates; if there is only distension without swelling, it is called Drum Distension [Gu Zhang], caused by Liver wood overacting on Spleen earth, which is difficult to treat. If swelling/distension is better in the morning and worse in the evening, it indicates Blood deficiency; if severe both morning and evening, it indicates Qi and Blood dual deficiency. If swelling spreads from the heart/abdomen to the four limbs, it is auspicious; if it spreads from the four limbs into the heart/abdomen, it is critical. For men, progression from below upwards is difficult to treat; for women, progression from above downwards is difficult to treat).
Treats masses (Zha Jia), hernias, and carbuncles/swellings.
Treats obstruction of the throat (Hou Bi) (Thinly sliced and stir-fried with vinegar, applied to the throat for good effect), and diseases caused by damp-heat pathogens.
Drains out Gu poison, applies to malignant sores, induces abortion, and causes hallucinations of seeing spirits.
Use the white flowers and roots (Red ones harm humans and can only be used for umbilical application; mix with 3 fen of Moschus [Shexiang], pound into paste, and apply; when urination becomes smooth, swelling subsides). Soak in Black Bean Decoction, steam, and use.
Works well with Allium Sativum (Suan, Garlic).
Datong (alias for Genkwanis Flos/Yuanhua), promotes water metabolism and removes fluid retention and phlegm accumulation.
Treats five types of water accumulations in the five Zang organs and skin, manifesting as distension, fullness, wheezing, urgency, pain radiating to the chest and hypochondrium, cough, and malarial patterns (The "five waters" refer to Wind Water, Skin Water, Correct Water, Stone Water, and Yellow Sweat. When water accumulates in the chest, hard and full like a stone, it is called Stone Water. When sweat resembles cypress juice, it is called Yellow Sweat; if not cured for a long time, it will inevitably lead to carbuncle and pus. Li Shizhen stated: Zhang Zhongjing treated Taiyang syndrome in Shanghan, where the exterior pattern was unresolved, water was retained in the epigastrium causing cough, dry retching, fever, or possibly wheezing or diarrhea; Xiao Qing Long Tang was primarily used. When the exterior pattern was resolved, accompanied by occasional headache, sweating, aversion to cold, water retained in the epigastrium, dry retching, pain radiating to both hypochondria, or possibly wheezing or cough; Shi Zao Tang was primarily used. Essentially, Xiao Qing Long Tang disperses exterior pathogens, allowing water to exit via sweat, which corresponds to "opening the ghost gates" in Nei Jing; Shi Zao Tang purges interior pathogens, allowing water to exit via urine and feces, corresponding to "cleaning the bladder and removing old accumulation" in Nei Jing. Shi Zao Tang consists of equal parts Yuanhua, Gansui, and Daji, with ten dates).
Leaves resemble willow leaves; purple-green flowers bloom in February; leaves emerge before flowers fall. Older stored material is superior. Boil with vinegar, soak in water, and sun-dry before use. The root treats scabies and can be used to poison fish.
Incompatible with Glycyrrhizae Radix et Rhizoma (Gancao) (Litigants would rub the leaves on the skin to cause redness and swelling, feigning injury to falsely accuse others).