Pyrrosia lingua, an amazing TCM herb to treat stranguria

What is pyrrosia lingua(Shi Wei)?
This is a species of epiphytic fern that is a member in the family Polypodiaceae. However, in TCM it is not the only medicinal source of Shi Wei, which also refers to the dried leaves of Pyrrosia sheareri (Bak.) Ching, Pyrrosia petiolosa (Christ) Ching, Pyrrosia gralla (Gies.) Ching, Pyrrosia davidii (Bak.) Ching, and so on. And other common names of this herb include Tongue Fern, Pyrrosia Leaves, Folium Pyrrosiae, Japanese Felt Fern, and more. It grows wildly throughout China, especially in provinces of Taiwan, Zhejiang, Hubei, and Hebei. It can be harvested throughout the year. And the following process is to chop off the roots and rhizome, remove the impurities, wash away the sand and soil, dry in the sun or beside a fire, and cut into sections. Typically it is used raw medicinally.

Pyrrosia lingua plant is 10 to 30cm in height. Slender, crosswise rhizome is densely covered with brown lanceolate scales. Leaves grow sparsely; petiole is 6 to 15cm long, slightly 4-edged, and with base that has joints and is covered with stellate hairs; blade is lanceolate, linear-lanceolate or oblong-lanceolate, 7 to 20cm long, 1.5 to 3cm wide, and acuminate apex, attenuate base, and entire margin. Sori are oval and scattered in the whole lower surface or in upper surface. Main habitats include rocks in the wild or trees.

Pyrrosia lingua health benefits
As mentioned above, this herb can be used for many different ailments. So, what is its mechanism? Now let’s take how it treats the upper urinary tract calculi as an example. This disease generally refers to the kidney or ureter stones, whose occurrence rate has increased in recent years, according to the reports. Its main clinical manifestations include activities-associated hematuria and pain, or renal colic caused by ureteral obstruction by stones. Currently, its leaf has been widely used in the treatment of the upper urinary tract calculi, thanks to its amazing ability of promoting diuresis to treat stranguria.

From point of view of Ben Cao Chong Yuan (The Esteemed Source of Materia Medica), pyrrosia herb bridges the intersection between the upward kidney essence and the downward lung essence. The upward water essence can help get though the upper and outside orifices; the descending lung qi can promote the circulation of waterway and thereby guide the urination back to normal.

Modern pharmacological actions of pyrrosia leaf
1) Its decoction has different degrees of inhibition on Staphylococcus aureus, Proteus, E. coli, and so on;
2) It has anti-viral, antitussive, and expectorant effects.