（宋开宝）
【气味】甘寒，无毒。
【主治】主五淋，败席尤良。
【核】曰∶出江南，及陕西泽地，他处虽有野生，但不多耳。丛生圆劲，与龙须草同类，
龙须草茎小瓤实，灯心草茎肥瓤虚为别也。土人选长大者，蒸熟待冷，劈取白瓤为炷，短细
者唯堪织席，用皮作蓑，谓之夫需。质之柔脆，性之温凉，各随水土，以分优劣。修事∶取
生劈者良，或饮或膏，或末或圆，各从方制。若辗末使，每用生劈白瓤十斤，以米粉调煮稀
薄浆水，拌润一伏时，晒燥辗末，入水澄去浆粉，取浮起者，曝干收用。
先人云∶外刚内柔，表青里白，具乙木之气，禀燥金之化。体浮用升，故能齐通窍穴，
咸遍腑脏，奇方之轻剂通剂也。
【 】曰∶草瓤用以然灯，与贞明不息之机矣。 弱而滑，轻虚而浮，端直而长。象一
阳之始生，自下而上，用行体至之发陈物也。顾肝之为用，疏泄前阴，不行焉，则为癃，为
淋，为水肿。又肝之为用，从踵彻巅，不及焉，则为急喉痹，为两胁 满；太过焉，则为眩
冒，为目不夜合。此不循伦次而允升，一唯迅疾而自上，所谓浮沉则顺之，反乎温凉则逆也。
（木自火出，性缘物显，用行体至，灯灯续明，柔以明升，积小以高硕，废固不行，缓
则不及，急则太过矣。）
[Song Kai Bao Ben Cao]
[Flavor and Properties] Sweet, cold, non-toxic.
[Indications] Mainly treats the five types of strangury (five categories of painful urinary disorders); using a worn-out mat is particularly effective.
[Analysis] It says: Produced in the Jiangnan region and wetlands of Shaanxi; although wild varieties exist elsewhere, they are scarce. It grows in clumps with round, tough stems, belonging to the same category as Dragon's Whisker Grass (Luzula japonica). The distinction lies in Dragon's Whisker Grass having thin stems with solid pith, whereas Juncus effusus (Rush Pith) has thick stems with hollow pith. Local people select the longer rushes, steam them until cooked, wait for cooling, split them open, and extract the white pith to use as lamp wicks. The shorter, thinner ones are only suitable for weaving mats, and their skins are used to make rain capes, called "Fu Xu". Its texture is soft and brittle; its nature of warmth or coolness varies by local soil and water conditions, determining its quality. Processing: Raw, split material is preferred. It may be used in decoctions, pastes, powders, or pills, according to prescription specifications. If powdering is required, take ten jin (approx. 5 kg) of raw, split white pith. Mix with a thin starch slurry made from rice flour, moisten thoroughly for one period of time (approx. 2-3 hours), dry in the sun, then grind into powder. Add water, clarify, remove the starch sediment, collect the floating fine powder, dry it in the sun, and store for use.
My late father said: Externally rigid and internally soft, green outside and white inside, it possesses the qi of Yi Wood (Liver Wood) and inherits the transformation of Dry Metal. Its body is light and floating, its action ascending; thus, it can unblock acupoints and permeate the zang-fu organs. It is a light and unblocking agent within extraordinary prescriptions.
It says: The rush pith is used to light lamps, embodying the mechanism of constant brightness without cessation. It is weak yet slippery, light, void, and floating, straight, upright, and long. It symbolizes the initial birth of Yang Qi, moving from below to above, executing the function of promoting the substance to reveal new growth. Regarding the Liver's function: it regulates the discharge of the anterior yin. If this function fails, it leads to retention of urine (Long), strangury, and edema. Furthermore, the Liver's function extends from the heel to the vertex. If this flow is insufficient, it results in acute throat bi (sore throat with obstruction) and distension/fullness in the hypochondrium; if excessive, it leads to dizziness and vertigo, and inability to close the eyes at night (insomnia). This refers to not following the proper sequence but rising swiftly from above. It is said that one should follow its floating and sinking nature; deviating from its warm/cool properties constitutes opposition.
(Wood emerges from fire; nature is revealed through objects; action promotes the substance to sincerity; lamps continue to shine; gentle light ascends; accumulating smallness to achieve greatness; abandoning solidity to avoid stagnation; being too slow leads to insufficiency, being too fast leads to excess.)