Songpan Cordyceps

Songpan Cordyceps

　　Songpan County is rich in Tibetan and Chinese medicinal herbs, with its grasslands and forests producing hundreds of varieties such as fritillaria, nardostachys, notopterygium, costus root, and cordyceps. Although the name “winter worm, summer grass” sounds unremarkable, its formation is quite fascinating.

　　Wu Qihé of the Qing Dynasty wrote in his *Illustrated Examination of Plant Names and Realities*: “In winter, it lives in the soil, its body like an old silkworm, covered in hair and capable of movement. By summer, the hair emerges above the ground, and the whole body stiffens into grass.” This is what is called “winter worm, summer grass.” The “old silkworm” here refers to the larva of insects such as the bat moth, which becomes rigid after being parasitized by fungi. These insects typically inhabit alpine thickets and meadows, generally at altitudes above 3,800 meters. They are found in rhododendron thickets dominated by small-leaf rhododendrons and extend into alpine meadow zones. The ascospores of the cordyceps fungus attach to the outer shell of the host larva and germinate under suitable conditions, with the fungal hyphae penetrating the host’s body cavity. Initially, the infected insect shows sluggish movement, then becomes restless and agitated. After a few days, the larva’s outer shell shows clear discoloration, shifting from deep brown-yellow to pale yellow. At this stage, the insect can still crawl slowly, and one can observe that its entire body is covered with gray-white fungal hyphae as it wriggles through rhododendron bushes and mugwort patches. From the Awakening of Insects to the Clear and Bright solar terms, the infection becomes most apparent, as the fungal hyphae inside the diseased larvae multiply rapidly. The infected insects move closer to soil areas rich in plant roots and burrow 4–8 centimeters below the surface before gradually dying and stiffening. While the larva is stiff underground, the fungal hyphae within its body cavity absorb nutrients and transition from the nutritional stage to the sexual stage. By the time of Grain Full or Grain in Ear, the larva’s body will be oriented vertically to the ground, with a club-shaped stroma emerging from its head and growing out of the soil. The so-called “grass” part of cordyceps refers to this stroma. Since the stroma typically emerges in spring and summer, it is called “summer grass.” The stroma is purplish-brown in color, with a slightly rough surface dotted with pinhead-sized protrusions visible to the naked eye. These tiny holes are openings to the asci cavities, inside which long, rod-shaped asci and slender, septate ascospores reside.

　　Cordyceps is believed to have first appeared in 1757 (the 22nd year of the Qianlong reign in the Qing Dynasty) in *Supplement to the Materia Medica* by Wu Yiluo, which explicitly noted its efficacy in “nourishing the lungs and kidneys, stopping bleeding and resolving phlegm, and treating tuberculosis-related coughs.” However, people were using it long before that. Tibetan people had already employed it medicinally, referring to it as “Yajia Gongbu,” which literally translates to “winter worm, summer grass.” There is also a claim that it was exported to Japan as early as the mid-Ming Dynasty.