宣、散风寒、温行水气、润肾燥。
辛温。散风寒。故诸风痹痛。咳嗽上气。头痛脊强者宜之。（颛治少阴之头痛。）辛散浮
热。
故口疮喉痹。（少阴火。）鼻渊齿 者宜之。（虫蚀脓烂。）水停心下则肾燥。细辛之辛。能行
水气以润之。（肾燥者、心亦躁、火屈于水、故躁也、经曰∶肾苦燥、急食辛以润之。）虽手
少阴引经。（心、）乃足少阴本药。（肾、）能通精气。利九窍。故惊痫耳聋鼻 。（鼻塞不闻
香臭、风寒湿热入于脑、故气不宣通、寒宜表、湿热宜清、有 肉者、为末吹鼻。）风眼泪
下倒睫。大便燥结者宜之。温经发汗。（能发少阴之汗、仲景治少阴证、反发热者、麻黄附
子细辛汤、乃治邪在少阴之表剂。）行血下乳。散结破痰。味浓性烈。不可多用。北产者细
而香。（华阴出者最佳。）南产者。稍大而不香。名土辛。又名马辛。（以其叶似马蹄也。）拣
去双叶者用。恶黄 、山茱萸。畏硝石、滑石。反藜芦。危亦村得效方、暗风卒倒、不省人
事
宣、散郁、通心肾。
苦泄热。温行气。辛散郁。主手少阴。（心、）能通肾气。上达于心。强志益智。聪耳明
目。
利九窍。治迷惑善忘。惊悸不寐。（诸证皆因心肾不交所致。）皮肤中热。肾积奔豚。一切痈
疽。敷服皆效。（缪希雍本草经疏曰∶痈疽皆从七情忧郁恼怒而得、远志辛能散郁。）并善豁
痰。远志交通心肾。并无补性。虚而挟滞者。同养血补气药用。资其宣导。臻于太和。不可
多用独用。纯虚无滞者忌。山西白皮者佳。（山东黑皮者、次之。）去心。甘草水浸一宿用。
畏珍珠、藜芦。得茯苓、龙骨良。叶（名小草）益精补阴气。治虚损梦泄。（可于统柴胡内
拣
出用之。）
宣通、发散风寒、温通行散水气、滋润肾燥。
性味辛温。能发散风寒。所以各种风痹疼痛、咳嗽气逆、头痛项背强直者适宜使用。（专门治疗少阴经的头痛。）辛味能疏散浮热。
所以口疮喉痹（少阴火盛）、鼻渊齿龋（虫蚀脓烂）者适宜使用。（水液停聚在心下则导致肾燥。细辛的辛味，能够行散水气从而滋润它。）（肾燥的人，心也会躁动，是因为火被水郁遏，所以产生躁动，《内经》说：肾苦于燥，急用辛味食物来滋润它。）虽然它是手少阴心经的引经药，但其实是足少阴肾经的本药。（细辛入肾经。）能够通达精气，利九窍。所以惊痫耳聋鼻塞（鼻塞不闻香臭，是风寒湿热侵入脑部，导致气机不通畅，寒邪宜用表法，湿热宜用清法，有息肉者，研末吹鼻。）风泪下流、倒睫、大便燥结者适宜使用。温通经脉发汗。（能发少阴经之汗，张仲景治疗少阴证，出现反发热症状时，使用麻黄附子细辛汤，这是治疗邪气在少阴经表层的方剂。）行血下乳，散结化痰。味道浓厚，性质猛烈，不可多用。北地产的细辛细小而香。（华阴出产的最好。）南地产的稍大且不香，称为土辛，又名马辛。（因为它的叶子像马蹄形状。）拣去双叶的（注：此处原文可能有误或指特定部位，通常指去心或去芦头，依原文保留“拣去双叶者用”）使用。忌恶黄芩、山茱萸。畏硝石、滑石。反藜芦。危亦林《得效方》中记载，治疗暗风突然昏倒，不省人事……
宣通、发散郁结、交通心肾。
苦味泄热，温通行气，辛味散郁。主治手少阴心经。（细辛入心经。）能够通达肾气，上达于心。增强意志，益智力，聪耳明目。
利九窍。治疗迷惑健忘、惊悸失眠。（这些病症都是因为心肾不交所致。）皮肤中的热感，肾积奔豚，一切痈疽，外敷内服都有效。（缪希雍在《本草经疏》中说：痈疽多因七情忧郁恼怒而得，远志辛味能散郁结。）并且善于豁痰。远志能交通心肾，并没有补益作用。虚证兼有滞涩者，需配合养血补气药用，借其宣导之力，达到太和境界。不可多用或单独使用。纯虚无滞者忌用。山西产的白皮远志为佳。（山东产的黑皮远志，质量次之。）去心，用甘草水泡一夜后使用。
畏珍珠、藜芦。与茯苓、龙骨同用效果好。叶子（名为小草）益精补阴气。治疗虚损梦遗。（可以从统柴胡中拣出使用。）
To promote circulation, disperse wind-cold, warm and move fluid retention, and moisten Kidney dryness.
Pungent and warm. Disperses wind-cold. Therefore, it is suitable for various wind-bi pain, cough with qi rebellion, headache, and stiffness of the spine and neck. (Specifically treats headaches of the Shaoyin channel.) Its pungency disperses floating heat.
Therefore, it is suitable for mouth ulcers and throat obstruction (Shaoyin fire), nasal sinusitis, and rotting teeth (caused by worms, pus, and decay). When water stagnates under the heart, it leads to Kidney dryness. The pungency of Xixin (Asari Radix et Rhizoma) can move fluid qi to moisten it. (When the Kidney is dry, the Heart is also restless; this is because Fire is constrained by Water, leading to restlessness. The Classic says: "The Kidney suffers from dryness; urgently eat pungent foods to moisten it.") Although it serves as a guiding herb for the Hand-Shaoyin (Heart), it is fundamentally a herb for the Foot-Shaoyin (Kidney). It can unblock essence and qi, benefit the nine orifices. Therefore, it is suitable for fright epilepsy, deafness, nasal congestion (nasal blockage where one cannot smell fragrances or odors, caused by wind-cold-damp-heat entering the brain, leading to blocked qi transmission; cold should be treated with exterior-releasing methods, damp-heat with clearing methods; for polyps, grind into powder and insufflate into the nose), tearing in wind, inverted eyelashes, and dry constipation. It warms the meridians and induces sweating. (It can induce sweating of the Shaoyin channel. Zhang Zhongjing used Mahuang Fuzi Xixin Tang (Ephedra, Aconite, and Asari Decoction) to treat Shaoyin syndrome with fever, which is an exterior-releasing formula for pathogens in the Shaoyin exterior.) It promotes blood circulation and lactation, dissipates nodules, and breaks down phlegm. Its flavor is rich and nature fierce; it should not be used in large doses. Northern Asari is thin and fragrant. (Those from Huayin are the best.) Southern Asari is slightly larger but not fragrant, known as Tuxin (Earth Asari) or Maxin (Horse Asari) (because its leaves resemble horse hooves). Use those from which double leaves have been removed. It is incompatible with Huangqin (Scutellariae Radix) and Shanzhuyu (Corni Fructus). It fears Xiaoshi (Natrii Sulfas) and Huashi (Talcum). It is inversely compatible with Lilu (Veratri Radix). Wei Yilin's *Defang* records that for sudden collapse due to hidden wind, loss of consciousness...
To promote circulation, dissipate depression, and connect Heart and Kidney.
Bitter flavor drains heat, warm nature moves qi, pungent flavor dissipates depression. It governs the Hand-Shaoyin (Heart). It can unblock Kidney qi and reach up to the Heart. It strengthens willpower, benefits intelligence, clarifies ears and eyes, and benefits the nine orifices.
It treats confusion and forgetfulness, palpitations, and insomnia. (All these conditions are caused by the failure of communication between Heart and Kidney.) It treats heat in the skin, Renji Ben tun (abdominal mass rising like a bull), and all types of carbuncles and sores; both external application and internal administration are effective. (Miao Xiyong stated in *Bencao Jing Shulou*: "Carbuncles and sores often arise from emotional depression, frustration, and anger; Yuanzhi's pungency can dissipate depression.") It is also good at resolving thick phlegm. Yuanzhi (Polygalae Radix) connects Heart and Kidney but has no tonifying properties. For deficiency patterns accompanied by stagnation, it should be used together with blood-nourishing and qi-tonifying herbs to leverage its promoting and guiding action, achieving supreme harmony. It should not be used in large doses or exclusively. It is contraindicated for pure deficiency without stagnation. White-barked Yuanzhi from Shanxi is superior. (Black-barked Yuanzhi from Shandong is inferior.) Remove the core, soak in Licorice water overnight before use.
It fears Zhenzhu (Pearl) and Lilu (Veratri Radix). It works well with Fuling (Poria) and Longgu (Fossilized Bones). The leaves (named Xiaocao) nourish essence and tonify Yin qi. They treat deficiency damage and nocturnal emissions. (They can be selected from Tong Chaihu [Total Bupleuri Radix] for use.)