What is Poria? A quick guide to the latest scientific explanation
Poria, commonly known as Yunling, Songling, and Fuling, is a fungus that parasitizes the roots of pine trees. It resembles a sweet potato, with a dark brown outer skin and a white or pinkish interior. Its original form is the dried sclerotium of the fungus Poria cocos in the family Polyporaceae, which mostly parasitizes the roots of masson pine or Japanese red pine. It is produced in Yunnan, Anhui, Hubei, Henan, Sichuan, and other places. It is mostly harvested from July to September. After digging it out, remove the mud and sand, pile it up for “sweating,” then spread it out to dry until the surface is dry, then “sweat” it again, repeating several times until wrinkles appear and most of the internal moisture has dissipated, then dry it in the shade. This is called “whole Poria.” Alternatively, fresh Poria can be cut into pieces by different parts and dried in the shade, separately called “Poria blocks” and “Poria slices.”
The Poria mycelium includes two types: monokaryotic and dikaryotic mycelium. The monokaryotic mycelium, also called primary mycelium, is formed by the germination of Poria spores and exists only in the early stage of germination. The dikaryotic mycelium, also called secondary mycelium, is the main form of the mycelium and is formed when two monokaryotic mycelia of different sexes meet and undergo plasmogamy. The mycelium appears white and fluffy, with distinctive multi-concentric ring-patterned colonies. Under a microscope, the mycelium can be seen to be composed of many branched hyphae. The hyphae are divided by septa into linear cells, about 2 to 5 micrometers wide, with clamp connections commonly seen at the tips.
The Poria sclerotium is a dormant body formed by a large number of hyphae and nutrients tightly gathered together. It is spherical, ellipsoidal, oblate, or irregularly block-shaped. Small ones weigh several liang, while large ones weigh several jin or several dozen jin. When fresh, it is soft and easy to break open; after drying, it is hard and difficult to break open. The outer layer of the sclerotium is crust-like, with a rough surface and tumor-like wrinkles. When fresh, it is light brown or brown; after drying, it becomes dark brown. The interior of the crust is white and light brown. Under a microscope, the hyphae in the white part of the sclerotium are mostly lotus-root-node-shaped or in mutually compressed masses. Near the crust are relatively slender, densely arranged light brown hyphae.
The Poria fruiting body usually grows on the surface of the sclerotium, and occasionally on older mycelium. It is honeycomb-like, varies in size, sessile and flat-lying, about 0.3 to 1 cm thick. It is initially white and becomes lignified and light yellow with age. The hymenium is borne on the inner surface of the pore tubes and is composed of numerous basidia. Each mature basidium produces 4 spores (basidiospores). Poria spores are grayish white, long ellipsoidal or nearly cylindrical, with one slanted tip, 6×2.5 to 11×3.5 micrometers.
Poria is sweet, bland, and neutral in nature and flavor, and enters the heart, lung, and spleen meridians. It has the effects of draining dampness and promoting diuresis, strengthening the spleen and harmonizing the stomach, and calming the heart and soothing the mind. It can treat difficult urination, edema and abdominal fullness, phlegm-fluid cough and counterflow, vomiting, severe morning sickness, diarrhea, seminal emission, strangury and turbid urine, palpitations, forgetfulness, and other conditions. The ancients called Poria the “divine medicine of the four seasons” because its effects are very broad and not limited to any season. When combined with various medicines, it can exert its unique effects regardless of cold, warm, wind, or damp diseases.