Also known as Medulla Junci in Latin name and common rush or soft rush in common name, medicinally it refers to the dry pith of Juncus effusus L. [J. Effusus L.Var.Decipiens Buchen.; J.decipiens (Buchen.) Nakai], a plant in the family Juncaceae. Hence it is sometimes called rush pith too. In China it is native to Jiangsu, Sichuan, Yunnan, Guizhou and other places. For medicinal uses, this herb is usually harvested from late summer to autumn. After that, keep the stems, dry them in the sun, take the pith out, sort them out, and tie them into bundles.

Juncus plant is a perennial herb, 40 to 100cm in height. Rhizome grows horizontally, with dense fibrous roots. Stems are tufted, erect, slender, cylindrical, 1.5 to 4cm in diameter, and full of white pith inside, which accounts for most of the space. Sheaths are reddish-brown or yellowish in color and sometimes up to 15cm in height. Leaf blade degrades into spine like shape. Inflorescence is pseudo lateral, cymose, flowery, and dense or sparse. Bracts connected with stems are 5 to 10cm long. Rush flower is pale green, 2 to 2.5cm long, and with short handle. Capsule is oblong, apex obtuse or emarginate, as long as or longer than the perianth, with 3 complete diaphragms inside. Seeds are numerous, ovate-oblong, brown, and about 0.4mm. Juncus effusus flowering time is from June to July and fruiting time from July to October.

PROVEN JUNCUS RELATED HERBAL REMEDIES 
In the field of Traditional Chinese Medicine (TCM), Juncus is believed as sweet, tasteless, and slightly cold in properties. And it covers 4 meridians such as heart, lung, bladder and small intestine. Its chief functions are treating stranguria by promoting diuresis and clearing heart by reducing pathogenic fire. Main Juncus effusus uses and indications are stranguria, Edema, difficult urination, damp-heat jaundice, vexation and sleeplessness, infantile nocturnal fretfulness, Acute Pharyngitis, mouth sores, trauma, and more. Recommended decoction dosage is from 1 to 3 grams in dried herb and from 15 to 30 grams in fresh herb.

Juncus Effusus

1) Deng Xin San
Deng Xin San is from Pu Ji Fang (Prescriptions of Universal Relief). This is primarily used for the symptoms after the eruption of measles, including irritation, wheezing, and difficult urination. In this formula Juncus effusus joins hands with Soft Turtle Shell (Bie Jia) to enhance the efficacy.

2) Deng Xin Zhu Ye Tang
Deng Xin Zhu Ye Tang is from Zheng Zhi Zhun Sheng (The Level-line of Patterns & Treatment). This prescription is principally used to treat irritability due to heart heat, Insomnia and sleeplessness, and nocturnal fretfulness infants. The other herb in this formula is Dan Zhu Ye (Lophatherum).

3) Xuan Qi San
Xuan Qi San comes from Dan Xi Xin Fa (Dan Xi's Heart Methods of Treatment). This formula is mainly formulated for sharp pain due to retention of urine. Other major herbal ingredients include Mu Tong (Akebia Caulis), Hua Shi (Talcum Powder), Dong Kui Zi (Musk Mallow Seeds), Zhi Zi (Gardenia), and Gan Cao (licorice root).

4) Tian Yi Wan
Tian YI Wan comes from Han Shi Yi Tong (Han's Book of Medicine). This prescription is basically designed for cleaning out water passages. The rest of other herbs are Fu Ling (Poria), Talcum Powder, Zhu Ling (Polyporus Sclerotium), Ze Xie (Water Plantain Root), and Ren Shen (Ginseng).