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Psoraleae Fructus (i.e., Poguolipi)
Taste: bitter, pungent. Nature: greatly warm. Non-toxic. Produced in various prefectures of Guangxi. The seeds are round and flat, green in color. Soak in salted wine overnight; discard those floating on the surface as they are light and void. Steam them, then dry in the sun. Alternatively, stir-fry together with black sesame seeds until cooked, then remove the sesame and use alone; or crush into pills adding walnut meat, plus Eucommiae Cortex (Duzhong) and blue vitriol salt (Qingyan). (This is Qing'e Wan.) Treats men's consumptive injuries, cures women's blood and qi disorders. Extremely effective for soreness and pain of the waist and knees; remarkable merit for bone marrow damage and degeneration. Eliminates dampness in the scrotum and reduces urination frequency; secures essence against slipping and revitalizes the yang pathway. Dispels various wind-damp bi syndromes; removes cold pain in the four limbs. Dislikes Licorice Root (Gancao); this must be known. Avoids Rapeseed (Yuntai) and mutton.

Wenchuan Notopterygii Rhizoma et Radix (Qianghuo)
Wenchuan Angelicae Pubescentis Radix (Duhuo)
Taste: bitter, sweet, pungent. Nature: neutral, slightly warm. The aroma and taste are both light; ascending, yang. Non-toxic. Mostly produced in Sichuan and Shu regions, also found in Longxi.
It does not sway when there is wind, but moves automatically when there is no wind, hence also named "Duyao Cao" (Swaying Grass). Originally the same species as Duhuo, later divided into two names. Those with purple color and dense nodes are Qianghuo; those yellow and forming blocks are Duhuo. Currently, physicians mostly use the whip-node parts for Qianghuo, and the "ghost eye" parts for Duhuo. Qianghuo has a vigorous qi, while Duhuo has a fine fragrance. The vigorous qi enters the Foot-Taiyang Bladder Channel; the fine fragrance enters the Foot-Taiyin Spleen Channel. Thus it is known that Qianghuo and Duhuo are originally channel-guiding herbs for the exterior and interior of the Hand and Foot-Taiyang channels, and also enter the Foot-Shaoyin Kidney Channel and Foot-Jueyin Liver Channel.
Ranked among the Sovereign herbs, it is not a weak or submissive agent. It truly rectifies chaos and restores order, achieving great things. Therefore, it penetrates everywhere without exception, and unblocks all obstructions. It can disperse wind pathogens invading the muscle and surface, and excels at benefiting pain in all joints of the body. It expels abscesses with muscle rot from the Great Yang (Taiyang), and eliminates old and new wind-damp syndromes. One must remove the black skin and rotten parts; only then will decoction and administration yield miraculous effects. If added Chuanxiong Rhizoma (Chuanxiong), it immediately stops headache in its own channel. Duhuo's main indications differ slightly from Qianghuo; it serves as the channel-guiding herb for the exterior and interior of the Foot-Shaoyin Kidney Channel.
It specifically treats gouty arthritis and latent wind in the Shaoyin channel, but does not treat the Taiyang channel. Therefore, for wet bi syndrome in both legs causing inability to move or walk, no other herb can cure it except this one. For toothache and dizziness caused by wind toxicity, this herb is suitable for treatment. Although it treats latent wind, it also aids in drying dampness. The classics state: "Wind can overcome dampness." However, sellers nowadays often harvest Tu Danggui (Radix Angelici Dahurici var. or similar substitutes) to pass off as genuine, so careful discrimination is necessary.
(Chen Jiamo) Commentary: "Huibian" states that since Qianghuo and Duhuo are described as the same species in the "Shennong Bencao Jing" with no separate entries, it is evident they are not two different substances. Later generations, seeing slight differences in shape, color, and aroma, established divergent theories. They failed to consider that inequality among things is the nature of things. Thus, although Qianghuo and Duhuo are of the same species, within one species there are variations: some are tight and solid, others are light and void. Zhang Zhongjing used Duhuo to treat Shaoyin conditions, selecting only the tight and solid ones; Li Dongyuan used Qianghuo to treat Taiyang conditions, selecting only the light and void ones. This is just like Huangqin (Scutellariae Radix): taking the withered and floating ones named Suqin for treating Taiyin conditions; taking the round and solid ones named Ziqin for treating Yangming conditions, following the same principle. Moreover, ancient formulas used only Duhuo, while modern formulas use both Duhuo and Qianghuo. Is it unknown whether the disease requires both, or is it simply that they have not investigated?
See the commentary after Sanggen Baipi (Morus Albae Cortex) in Volume 4 for reference.