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A single stem grows straight upward, not swayed by the wind; hence it is called *Duhuo* (Radix Angelicae Pubescentis). The *Shennong Bencao Jing* records that *Duhuo* has another name, *Qianghuo* (Rhizoma Notopterygii), because it grows in the Qiang region.

Tao Hongjing stated that *Qianghuo* originates from the Qiang lands, whereas the variety produced in Yizhou and Xichuan is called *Duhuo*, implying that one plant yields two types. Li Shizhen (styled Binhu) cited various theories to argue that *Duhuo* and *Qianghuo* are two varieties of the same category: those produced within China proper are *Duhuo*, while those from Western Qiang are *Qianghuo*. Their clinical applications differ slightly. It is incorrect for later practitioners to classify them as two distinct substances. Furthermore, the *Duhuo* produced by the Qiang people in Sichuan constitutes yet another variety, which is also usable.

The root is warm in nature, with a bitter and acrid taste. Its qi and flavor are both thin, possessing a floating and ascending quality, thus belonging to Yang. It is a wind-dispelling herb acting on the Hand and Foot Taiyang meridians, and also enters the Qi aspect of the Foot Jueyin and Foot Shaoyin meridians. It treats pathogenic wind lingering at the exterior or in the upper body, expelling wind pathogens from the Bladder and between the Kidneys. It addresses headaches of the Taiyang meridian (The Great Yang meridian runs from head to foot; only the Jueyin meridian and the Du vessel intersect at the vertex. If qi rebels and ascends, preventing the descent of all Yang meridians, pain ensues). It alleviates generalized body pain, joint pain, neck stiffness, and spinal pain, and can search out Liver wind and drain Liver qi (It is used in *Xieqing Wan* because Ren Water and Yi Wood converge here). It treats various wind-induced tremors and vertigo, facial paralysis (deviation of mouth and eyes). In cases where wind-dampness mutually attacks, or in bi-syndrome caused by wind-cold-dampness, manifesting as soreness, pain, numbness, tendon contraction, and curling of limbs, general numbness, and blood stasis lesions (Although it does not directly treat blood deficiency causing dry tendons, it may be used concurrently with blood-nourishing herbs when complicated by wind-dampness). It also dissipates toxic pus and stale blood (from various Materia Medica texts).

*Qianghuo* has clear, ascending qi belonging to Yang; it excels at moving the Qi aspect, is expansive rather than constrictive, ascending yet capable of descending, vigorous and good at dispersing. Thus, it enters the Hand and Foot Taiyang meridians to regulate wandering wind. Although its functions appear different from *Duhuo*, they are actually mutually complementary as interior-exterior pairs (Shicai). Bones are the external correspondence of the Kidney of the Shaoyin meridian. Although *Qianghuo* is a wind-herb of the Taiyang meridian, since Taiyang and Shaoyin are interior-exterior partners, *Qianghuo* also enters the Shaoyin. However, it focuses specifically on reaching the Qi aspect of the Great Yang (Taiyang), whereas the Blood aspect of Shaoyin should rely more on *Duhuo*. Therefore, treating Lijie wind-pain requires the combined use of both *Qianghuo* and *Duhuo*, along with Pine Node (*Songjie*). The combination of *Qianghuo*, *Duhuo*, and *Fangfeng* collectively manages neck stiffness and spinal pain due to Du vessel pathology (because the Foot Taiyang meridian runs alongside the Du vessel, and the Hand Taiyang meridians intersect with the Du vessel at Dazhui, where all Yang meridians meet; thus, these three herbs form a formula treating Du vessel disorders) (Dongyuan). To raise Middle Jiao qi, Chaihu and Shengma are used; to raise Lower Jiao qi, Ben Qianghuo is used.