味辛，温，无毒。主上气咳逆，结气，喉痹，吐吸，心痛，胁风，胁痛，温筋通脉，止
烦出汗，利关节，补中益气，
久服通神，轻身、不老。生南海山谷。南海郡即是广州。今俗用牡桂，状似桂而扁广殊薄，
皮色黄，脂肉甚少，气如木
兰，味亦类
桂，不知当是别树，为复犹是桂生，有老宿者耳，亦所未究。
〔谨案〕《尔雅》云∶ ，
木
牡桂，即今木桂，及单名桂者，是也。此桂花子与菌桂同，唯叶倍长，大小枝皮俱名牡桂。
然大枝皮肌理粗虚如木兰，
肉少味薄，不及小枝皮也。小枝皮肉
多，半卷。中必皱起，味辛美。一名肉桂，一名桂枝，一名桂心。出融州、柳州、交州甚良
。
味甘、辛，大热，有毒。主温中，利肝肺气，心腹寒热，冷疾，霍乱，转筋，头痛、腰
痛
嗽、鼻 ，能堕胎，坚骨节，通血脉，理疏不足，宣导百药，无所畏，久服神仙，不老。生
桂阳。二月、七、八月、十
月采皮，阴干。
得人参、麦门冬、甘草、大黄、黄芩调中益气，得柴胡、紫石、干地黄疗吐逆。案《本
经》唯有菌桂、牡桂，而无
此桂，用体大同小异，今俗用便有三种。以半卷多脂者单名桂，入
应。《仙经》乃并有三种桂，
常服食，以葱涕合和云母蒸化为水者，正是此种耳。今出广州湛惠为好，湘州、始兴、桂阳
县即是小桂，亦有，而不如
广州者，
交州、桂州者形段小，多脂肉，亦好。《经》云桂叶如柏叶，泽黑，皮黄心赤。齐武帝时，
湘州送桂树，以植芳林苑中，
今东山有山桂皮，气粗相类，而叶乖异，亦能凌冬，恐或者牡桂，时人多呼丹桂，正谓皮赤
耳。北方今重此，每食辄须
之。盖《礼》所云姜桂以为芬芳也。
〔谨案〕菌桂，叶似柿叶，中有纵文三道，表衷无毛而光泽。牡桂叶长尺许，陶云小桂，
或
言其叶小者。陶引《经》云∶叶似柏叶，验之殊不相类，不知此言从何所出。今案桂有二种
，唯皮稍不同，若菌桂老皮坚板无肉，全不堪用。其小枝皮薄卷，乃二、三重者，或名菌桂
，或名筒桂。其牡桂嫩枝皮，名为肉桂，亦名桂枝。其老者，名牡桂，亦名木桂，得人参
等良。本是菌桂，剩出单桂条，陶为深误矣。
[Mugui (Cortex Cinnamomi)]
Taste: Acrid. Nature: Warm. Toxicity: Non-toxic. Indications: Governs rebellious Qi with cough and wheezing, stagnant Qi, throat obstruction (sore throat with swelling and difficulty swallowing), rapid inhalation and exhalation, heart pain, wind in the hypochondrium, hypochondriac pain, warms the sinews and unblocks the collaterals, stops vexation and sweating, benefits the joints, tonifies the middle and supplements Qi. Long-term use can enhance spiritual clarity, lighten the body, and prevent aging. Grows in the valleys of Nanhai. The commandery of Nanhai is Guangzhou. Currently, the variety commonly used is Mugui. Its appearance resembles Cinnamon but has flatter, broader, and thinner leaves. The bark is yellowish, with very little aromatic flesh. The odor resembles Magnolia officinalis (Houpo), and the taste is similar to Cinnamon. It is unclear whether this is a different tree or simply older Cinnamon; this remains unresolved.
[Commentary] The *Erya* states: "Mugui of the tree," which refers to the current Mugu (Wood Cinnamon) and simply "Gui" (Cinnamon). The flowers and seeds of this Cinnamon are the same as those of Jun Gui (Thin-barked Cinnamon); only the leaves are twice as long. The bark from both large and small branches is called Mugui. However, the bark from large branches has a coarse, loose texture resembling Magnolia officinalis, with little flesh and a weak flavor, inferior to that from small branches. The bark from small branches has more flesh and curls halfway. The center is often wrinkled, and the flavor is acrid and pleasant. It is also known as Rougui (Thick-barked Cinnamon), Guizhi (Cinnamon Twig), and Guixin (Cinnamon Heart). High-quality specimens come from Rongzhou, Liuzhou, and Jiaozhou.
[Gui (Cinnamon)]
Taste: Sweet, Acrid. Nature: Very Hot. Toxicity: Toxic. Indications: Warms the middle, benefits Liver and Lung Qi, treats cold-heat sensations in the heart and abdomen, cold diseases, cholera, muscle cramps (tetany), headache, lower back pain, cough, nasal discharge (rhinorrhea), can induce abortion, strengthens bone joints, unblocks blood vessels, regulates deficiency in the pores, guides all medicines, has no contraindications, and long-term use leads to immortality. Grows in Guiyang. Harvest the bark in February, July, August, and October; dry in the shade.
When combined with Ginseng Radix et Rhizoma (Renshen), Ophiopogonis Radix (Maidong), Glycyrrhizae Radix et Rhizoma (Gancao), Rheum Radix et Rhizoma (Dahuang), and Scutellariae Radix (Huangqin), it harmonizes the middle and supplements Qi. When combined with Bupleuri Radix (Chaihu), Psilopyritum (Shizhuyu), and Rehmanniae Radix Preparata (Shudihuang), it treats vomiting and reflux. According to the *Shennong Ben Cao Jing*, there were only Jun Gui and Mugui, without this specific "Gui." Their medicinal properties are largely similar with minor differences. Currently, three types are commonly used. The variety that is half-curling and rich in oil is simply called "Gui" and should be used for medicinal purposes. The *Immortal Classics* list three types of Cinnamon. For constant consumption, mixed with scallion juice and cloud mother (Yunmu) and steamed into water, this is the correct type. Currently, specimens from Zhanhui in Guangzhou are considered the best. Those from Xiangzhou, Shixing, and Guiyang counties are referred to as Xiao Gui (Small Cinnamon); they are available but inferior to those from Guangzhou. Specimens from Jiaozhou and Guizhou have smaller segments but are rich in oily flesh and are also good. The classic text states that Cinnamon leaves resemble Arborvitae leaves, are dark green and glossy, with yellow bark and red inner wood. During the reign of Emperor Wu of Qi, Cinnamon trees were sent from Xiangzhou and planted in the Fanglin Garden. Today, there is wild Cinnamon bark on Dongshan Mountain; its odor is coarse and similar, but the leaves are distinct. It can withstand winter, suggesting it might be Mugui. People at the time often called it Dangui (Red Cinnamon), referring specifically to the reddish bark. In the North, this herb is currently highly valued and required with every meal. This likely corresponds to the "Ginger and Cinnamon for fragrance" mentioned in the *Book of Rites*.
[Commentary] Jun Gui leaves resemble Persimmon leaves, with three longitudinal veins in the center, smooth and glossy on the surface. Mugui leaves are about one chi long. Tao Hongjing referred to Xiao Gui, saying some claim its leaves are small. Tao cited the *Ben Cao Jing* stating the leaves resemble Arborvitae, but verification shows they do not match at all; the source of this statement is unknown. Current examination shows two types of Cinnamon, differing slightly in bark. Old bark of Jun Gui is hard, board-like, and lacks flesh, making it unusable. Thin, curled bark from small branches, forming two or three layers, is named either Jun Gui or Tong Gui (Tube Cinnamon). Tender branch bark of Mugui is named Rougui or Guizhi. Older Mugui is named Mugui or Mugu. It works well when combined with Ginseng etc. Originally, this was Jun Gui. The separate entry for "Single Gui" is an error by Tao Hongjing.