Chinese herb of the week: Qualities and uses of Gui Zhi (Cinnamon Twig)

I thought I’d start a repeating feature – Herb of the Week ! I’ve noticed that quite a few readers are interested in reading about herbs and you all seem to like quickly usable information – so each Herb of the Week post will contain the following features:

• Description of the herb as a growing plant, a dried herb and in its common prepared forms, if any – PICTURES!!!
• Any interesting biological, historical or cultural information about the herb – including Chinese language etymology
• Common TCM uses of the herb
• CCM uses of the herb
• Possibly some deeper descriptions of the pathologies involved, when there is room

This week, we’re going to start with Gui Zhi, known in English as Cinnamon twig.

The plant

• Latin name/Pharmaceutical name: Cinnamomum cassia/Cinnamomi Ramulus
• Other common names: Cassia, Chinese Cinnamon – my research indicates that the cinnamon used here is different from the most common culinary type used. Because of this association, it is sometimes called bastard cinnamon or poor-man’s cinnamon.

• The growing plant: As I have never seen the growing plant, I’m going to have to outsource the physical description of the plant to someone better qualified – see Ms. Grieve on Cassia.
• The dried herb: I’ve seen a few different forms – but the most common looks as if it is cut on a diagonal – it typically includes the bark even though some sources indicate all but the very thinnest bark should be removed. I can’t find a better picture than this at the moment:

Bensky’s unparalleled Materia Medica (link below) indicates that one should look for “young twigs without leaves or any withered parts.” From what I understand the thinner the twig, the better.

• Common preparations: Many different parts of the Cinnamon plant are used, including the bark (Rou Gui) and twigs with bark removed (Gui Zhi Mu). As far as preparation goes, I could only find common use of honey-fried Gui Zhi – the addition of heat and honey increases the warming capacity of Gui Zhi but impedes its ability to release the exterior. Bensky lists dry frying as another preparation but that does not seem to be widely employed.

• Chinese properties: Gui Zhi is listed in the category of herbs called “herbs that release the exterior.” The most common way of thinking about this category is by relating them to the Western concept of diaphoresis. However, herbs that release the exterior are capable of much more than just promoting a sweat. In contemporary literature, Gui Zhi is considered to be warm in nature and both sweet and pungent in nature. It is said to enter the Heart, Lung and Bladder channels. In the Shen Nong Ben Cao Jing (神農本艸經) – also see link below, Gui Zhi is said only to be warm in nature and pungent in flavor – omitting the sweet flavor.
• It is interesting to note how the doctrine of signatures works in evaluating this herb. Compared to another part of the Cinnamon tree – Rou Gui or Cinnamon Bark – Cinnamon twig is relatively superficial, light and outward spreading. Rou Gui is closer to the heart of the tree, more protective and heavier.

Historical-cultural information about Gui Zhi

• Classical text descriptions: As already discussed above, the Shen Nong Ben Cao Jing (SNBCJ) describes Gui Zhi as being pungent in flavor and warm in nature. Another interesting thing in the SNBCJ – Gui Zhi is said to be good for counterflow Qi (vomiting, hiccough, etc) and situations where the Qi or breath are “bound up” and unable to move freely. Both of these are cases of fouled up movement – in the first, the movement is going in the wrong direction and in the second, the movement isn’t happening. This may relate to the pungency of Gui Zhi – it is capable of righting wrong movement and getting things moving that are stuck.

• Etymology of the characters: Let’s look at the characters for Gui Zhi again – 桂枝. The left character, guì, refers to the tree itself and doesn’t seem to be particularly interesting. However, the right hand part of that character – the 圭 – is both the phonetic but is also used to refer to a kind of jade tablet used by rulers as a symbol of their power. So clearly, the tree was regarded as powerful. The right character doesn’t reveal any particular insights that I can find – it just means branches or twigs!

Medical applications of Gui Zhi

• Common uses of Gui Zhi: This is one of the rare cases where TCM usage of the herb approximates what Classical texts indicate. Gui Zhi is often used in what TCM calls “deficient wind-cold attacks” which are, essentially, externally contracted illnesses (colds, flus) that involve sweating without provocation. Gui Zhi’s pungency and similar appearance to the energetic channels of the body also make it a prime candidate for use in unobstructing blocked channels as in Bi syndromes (bad pain in the body as one finds in arthritis and similar conditions).
• There are several other uses ranging from rectifying Heart Yang deficiency (with attendant palpitations and shortness of breath) to warming and tonifying the center to rectify deficiency cold of the Middle Jiao (with attendant diarrhea and noisy bowels.) REMEMBER – Gui Zhi does these things as a member of a FORMULA carefully constructed by a licensed practitioner of Chinese medicine – don’t go out and buy a bunch of cinnamon and consume it voraciously in an attempt to fix your arthritis symptoms.

• Shang Han Lun: In the Shang Han Lun we find support for the TCM notion that Gui Zhi (in the formula Gui Zhi Tang) should be used in cases where a pathogen has invaded and the balance between Ying and Wei has been disturbed, producing sweat where there should be none. Where TCM calls this “deficient wind attack” the Shang Han puts it in the category of Tai Yang disease, Wind strike exterior vacuity.
• Other Classical Texts: Recently in a class at NCNM, we learned about a new way to look at herbs using the five element model from a classical text called the Tang Ye Jing (汤液经). It was my first exposure to the book so my understanding is only very superficial. The five elements are used in a theory of “mutual containment” in this text. Regarding Gui Zhi, it is said to be the “wood herb of the wood class.” It exemplifies wood energy in its pungency – mimicking the outward spreading nature of living wood as we know it. As a wood herb, it may resonate with wind energy – wind being associated with the wood element. It is my understanding that it is partially this understanding of the herbs that motivated Shang Han Lun formula science, but again, I’m just beginning to delve into the text.

Eric

Tagged as: Character, chinese-herb, chinese-herbs, cinnamon, gui-zhi, herbs, shang-han-lun, tang-ye-jing