Hou Po, “the thick bark” of the magnolia

Hou Po reads “the thick bark”: the name first describes what makes the plant, the dense, grey-brown bark of a large magnolia (Magnolia officinalis) with fragrant, creamy-white flowers. The second character also means “simple, unadorned”, and some scholars read in it a straightforward plant that does what is expected of it. Its reference terroir is in Sichuan and Hubei, home of Chuan Po, considered the finest. Now rare in the wild, the tree is protected in China: the bark comes from plantations, where fifteen to twenty years must pass before the first harvest. A good bark, rolled into tight tubes, leaves an oily trace when scratched with a fingernail.

Making the Qi descend, lightening the belly

In traditional Chinese medicine, Hou Po is warm, bitter and pungent in flavour. Bitterness makes things descend and dries, pungency disperses, warmth opposes cold, heavy Dampness. Associated with the Spleen, Stomach, Lung and Large Intestine, it follows the descending path. The classical texts make it the leading herb for a bloated belly and fullness: when the Qi is blocked in the belly and everything fills up, it pushes this Qi downwards, whether the fullness comes from Dampness, food or arrested Qi. It can also bring the Lung Qi back down, which opens the chest.

Drying Dampness in the Middle

Its second gesture is to dry. When Dampness accumulates in the Spleen and Stomach, it weighs down the whole Middle; the bitterness of Hou Po dries it, its pungency disperses it, and the Spleen regains its ability to transform the Fluids. With atractylodes (Cang Zhu), it forms the basic pairing for Dampness in the Middle, at the heart of Ping Wei San. In almost all current prescriptions, the bark is prepared with fresh ginger juice: its harshness fades, it warms the Middle better and harmonises the Stomach better. Modern research has looked in particular at magnolol and honokiol.