出华山。根细而直。色紫而柔。味极辛。嚼之习习如椒而更甚于椒。其根曲者。
其色黄白或黑者
。其味虽辛而不甚。或兼微苦。或单苦。或甘者。皆非细辛。杜衡鬼督邮徐长卿白薇白前五
种
辛则横走。温则发散。）入足厥阴少阴血分。为手少阴引经药。（香味俱细。与独活相类。故
入少阴。龟龄集云。细而辛者。能通心窍。醋浸一宿。晒干为末用。）独活为之使。细指形
言。辛指味言。轻清柔韧。端直修长。当入少阳。宣达甲胆之用。自下而上。以行春令。故
东垣云。胆气不足。细辛补之。（之颐）主治风寒头痛。（治少阴头痛如神。以经气为阴寒盛
气所逆也。亦止诸阳头痛者。阴寒郁乎阳也。）寒咳上逆。温中下气。（寒散则气自下）益肝
胆。通精气。开胸中滞结。破痰利水。（气为寒所伤。故停水于上。痰亦即寒水所凝。不治
一切痰也。）疗百节拘挛。风湿痹痛。除喉痹。口舌生疮。散齿痛。（能散浮热亦火郁发之之
义。）通耳窍。及 鼻不闻香臭。止风眼下泪。下乳结。通血闭。治妇人血沥腰痛。（诸本草
）止少阴合病之头痛。杀三阳数变之风邪。（东垣） 温阴经。去内寒。治邪在里之表者
溪）密通精气。显益火。大青阳之象也。（复）润肝燥。（辛能达肾气即以润肝之阴气）治督
脉为病。脊强而厥者。（辛温以润。内寒所主头痛脑痛。拘挛痹痛。汗不出。血不行。皆从
阴中以通真阳之功。通真阳即以治督。好古） 同石膏。治阳明火热。上攻齿痛。得鲤鱼胆
青羊肝甘菊花决明子。疗目痛。得甘草。疗伤寒少阴咽痛。同黄连等分。为末。治口舌生疮。
漱涎甚效。或用黄柏。
〔论〕 细辛香味俱细。少阴本药也。其辛热能温足少阴之寒。究温寒之用。所以致于
内外周身。而上行为最者。非肝不能也。（肝合任而交督。自九地之下际于九天之上。）别录
所云益肝胆。通精气。最为扼要。其在至阴之分。虽不伦于补阳诸味。却能就阴分而散寒邪。
（如邪气在里之表。及拘挛痹痛。乳结血闭。皆自阴中通阳。）即至阳之分。虽难比于行气
诸剂。却能就阳分而散阴结。（如散胸中积滞。及头痛气逆。痰饮水聚。喉痹 鼻。皆在阳
中通阴。）阴中阳通。则能资荣气而使畅矣。（故又谓入厥阴少阴血分）阳中阴通。则能助风
剂而使行矣。（所以谓诸风通用）总以辛温达肾肝之气。而畅阳于下。导阴于上。纾肾阴而
升肝阳。最为有裨于人。而非益气血之药也。此味因洁古言诸风通用。而承袭者。往往不察
所宜。不知风从阳气言之。有虚有实。如阳郁于下而为风。自以达阳为主。若阳壅于上而为
风。即宜以和阴为主。反加辛温升散。则阳愈壅而风愈甚矣。细辛治阳郁之风。不治阳壅之
风。投之若误。为害滋甚。有中气虚而时患伤风。竟从补中气而愈者。不可参此义以用细辛
乎哉。至其能治风湿痹痛。亦由阳虚化风。因之化湿者也。凡阳虚郁风者多化湿。不可不知。
缪氏云。凡病内热。及火升炎上。上盛下虚。气虚有汗。血虚头痛。阴虚咳嗽。法皆禁
用。气浓性烈。入药不得过五分。
〔修治〕 双叶者。服之害人。须拣去。洗净泥沙。
Originating from Mount Hua. The root is slender and straight. It is purple in color and flexible in texture. Its taste is extremely pungent. When chewed, it produces a tingling sensation similar to that of Zanthoxylum (Sichuan pepper), but more intense. Those with curved roots, or those yellowish-white or black in color, or those whose pungency is not strong, or which have a slight bitterness, pure bitterness, or sweetness, are not true Asarum. (Du Heng, Gui Du You, Xu Chang Qing, Bai Wei, and Bai Qian, these five herbs, if pungent, move horizontally; if warm, they disperse.) Entering the blood aspect of Foot Jueyin Liver Channel and Foot Shaoyin Kidney Channel, it serves as a guiding herb for Hand Shaoyin Heart Channel. (Its fragrance and taste are both subtle, resembling Duzhuo [Angelicae Pubescentis Radix], thus entering Shaoyin. *Guiling Ji* states: Herbs that are fine and pungent can open the heart orifices. Soak in vinegar overnight, dry, and grind into powder for use.) Angelicae Pubescentis Radix (Duzhuo) acts as its assistant. "Fine" refers to its morphology, "pungent" refers to its taste. Light, clear, soft, and tough, upright, straight, and long, it should enter Shaoyang Channel, promoting the function of Jia Gallbladder. Moving from below upwards, it executes the spring-like generative qi, therefore Li Dongyuan said: For insufficiency of Gallbladder Qi, Asarum supplements it. (Zhang Yuansu) Mainly treats wind-cold headache. (Treats Shaoyin headache effectively, as the channel qi is reversed by excessive Yin-cold qi. It also stops various Yang channel headaches, due to Yin-cold stagnation in the Yang aspect.) Cold cough with rebellious Qi, warms the middle and directs Qi downward. (When cold disperses, Qi naturally descends.) Benefits Liver and Gallbladder, unites Essence and Qi, opens chest stagnation, breaks phlegm and promotes urination. (Qi injured by cold leads to water retention above. Phlegm is also congealed cold-water, not treating all phlegm syndromes.) Treats spasms and contractures of all joints, rheumatic bi-pain, removes throat obstruction, mouth and tongue sores, disperses toothache. (Can disperse floating heat, embodying the principle of "releasing fire stagnation"). Opens ear orifices, and nasal congestion causing loss of smell, stops tearing from wind-eye, resolves breast lumps, unblocks blood stasis, treats women's blood dribbling and lower back pain. (Various Materia Medica records) Stops headaches caused by combined Shaoyin disease, eliminates wind pathogens changing frequently in Three Yang channels. (Li Dongyuan) Warms Yin channels, removes internal cold, treats exterior symptoms where pathogen is interior. (Wang Haogu) Secretly unites Essence and Qi, visibly benefits True Fire, representing the image of Great Green Yang. (Li Gao) Moistens Liver dryness. (Pungency reaches Kidney Qi, thereby moistening Liver Yin). Treats Governor Vessel diseases, characterized by stiff spine and cold extremities. (Pungent-warmness moistens; headaches, brain pain, spasms, bi-pain, anhidrosis, and blood stasis caused by internal cold are all achieved through the merit of unblocking True Yang from Yin; unblocking True Yang treats the Governor Vessel. Li Shizhen) Combined with Gypsum Fibrosum (Shigao), treats Yangming fire heat attacking teeth causing toothache. With Cyprinus Carpio Bile (Liyudan), Capra Hircus Liver (Qingyanggan), Chrysanthemi Flos (Ganjuhua), and Cassiae Semen (Juemingzi), treats eye pain. With Glycyrrhizae Radix et Rhizoma (Gancao), treats Shaoyin sore throat in Shanghan. Mixed with equal parts of Coptidis Rhizoma (Huanglian), ground into powder, treats mouth and tongue sores; gargling is very effective. Alternatively, use Phellodendri Cortex (Huangbai).
[Discussion] Asarum's fragrance and taste are both subtle, being the primary herb of Shaoyin. Its pungent-warm nature warms the cold of Foot Shaoyin Kidney Channel. Investigating the application of warming cold, why its effect reaches inside and outside the whole body, with upward movement being the strongest, is non-other than the Liver's capability. (Liver connects with Ren Mai and intersects with Du Mai, extending from the depths of Nine Earths to the heights of Nine Heavens.) What *Shennong Bencao Jing* says about benefiting Liver and Gallbladder, and uniting Essence and Qi, is most concise. In the realm of extreme Yin, although it does not belong to Yang-tonifying substances, it can scatter cold pathogens within the Yin aspect. (Such as pathogen at the exterior of the interior, spasms, bi-pain, breast lumps, and blood stasis, all achieve Yang unblocking from Yin.) Even in the Yang aspect, although it cannot compare to Qi-moving formulas, it can scatter Yin knots within the Yang aspect. (Such as dissipating chest accumulation, headache with rebellious Qi, phlegm-fluid accumulation, throat obstruction, and nasal blockage, all achieve Yin unblocking from Yang.) When Yang unblocks within Yin, it nourishes Ying Qi making it smooth. (Thus said to enter Jueyin and Shaoyin Blood aspect). When Yin unblocks within Yang, it assists wind-dispersing agents to move. (Thus said to be general for all wind conditions). Overall, it uses pungent-warmness to reach Kidney and Liver Qi, smoothing Yang below and guiding Yin above, soothing Kidney Yin and ascending Liver Yang, which is most beneficial to humans, rather than being a Qi and Blood tonifying herb. Because Zhang Jiegu stated it is general for all winds, successors often failed to examine its suitability, not knowing that regarding Wind from the perspective of Yang Qi, there are deficiency and excess. If Yang is stagnant below causing wind, the main approach should be to reach Yang; if Yang is congested above causing wind, the approach should be to harmonize Yin. Adding pungent-warm ascending dispersants would only increase Yang congestion and worsen wind. Asarum treats wind caused by Yang stagnation, not wind caused by Yang congestion. Misuse causes great harm. There are cases of deficient Middle Qi suffering frequent common colds, cured by tonifying Middle Qi; one must not apply this meaning to use Asarum indiscriminately. Regarding its ability to treat rheumatic bi-pain, it is also because Yang deficiency transforms into wind, which then transforms into dampness. Generally, Yang deficiency with stagnant wind often transforms into dampness; this must be known. Miao Xiyong said: For diseases with internal heat, rising fire inflammation, upper excess and lower deficiency, Qi deficiency with sweating, Blood deficiency headache, and Yin deficiency cough, its use is contraindicated by law. Its aroma is strong and nature fierce; dosage in decoction must not exceed 2.5 grams (0.5 qian).
[Processing] Those with double leaves are harmful to consume and must be removed. Wash away mud and sand.