Introduction
Cordyceps is a rare and exotic medicinal mushroom, known in China for centuries. One that reportedly has a number of far reaching medicinal effects. Most people in the West have come to know this rare herbal medicine in only the last twenty years or so. During that time, modern scientific investigation into its seemingly miraculous range of healing powers has proven what Chinese practitioners have noted for centuries: That it works well in combating a myriad of medicals problems. This chapter is an overview of the description and uses for this once rare medicinal treasure.

Name and general description
A medicinal herb of long and illustrious history, Cordyceps sinensis is an Ascomycetes fungus closely related to the mushrooms. While not actually a mushroom in the taxonomic sense, it has been regarded as, and called, a medicinal mushroom throughout history. We will continue that tradition in this paper – referring to it as a mushroom. Please excuse such literary license.

The name Cordyceps comes from the Latin words: cord and ceps, meaning "club" and "head", respectively. The Latin conjugation accurately describes the appearance of the club fungus, Cordyceps sinensis, whose stroma or fruitbody extend from the mummified carcasses of insect larvae, usually caterpillar larva of the Himalayan Bat Moth, Hepialis armoricanus.

 In historical and general usage the term “Cordyceps” usually refers specifically to the specific species Cordyceps sinensis, but there are also many other closely related species that come under the general term of Cordyceps. While Cordyceps sinensis may be the species of Cordyceps that is most well known throughout the world, there are many other species in the genus Cordyceps in which modern science has found valuable medicinal properties in as well. In this paper we will generally use the term Cordyceps without the species designator, as many of the different species of Cordyceps fit the description and uses revealed herein. Where a specific species designation is important, that species name will be given as well.

Cordyceps sinensis
Cordyceps sinensis has been known and used for many centuries in Traditional Chinese Medicine (TCM). In nature, it is found only at high altitudes on the Himalayan Plateau, and is thus difficult to find and harvest. Because of the difficulties involved in harvesting this exotic medicinal, Cordyceps has always been one of the most expensive medicines known. This high price relegated it almost exclusively to members of the Emperor's court and other of the Chinese nobility, and it was historically beyond the reach of the average Chinese subject. Despite its cost and rarity, the unprecedented litany of medicinal uses for Cordyceps has made it a highly valued staple of the Chinese medical tradition.

A recognized wonder of the natural world for upwards of 2000 years in China and the surrounding Orient, knowledge of this incredible phenomenon only reached Western scientific audiences in 1726, when it was introduced at a scientific meeting in Paris. A Jesuit priest, who chronicled his experiences with the Cordyceps mushroom during his stay at the Chinese Emperor’s court, carried the first specimens back to France. (Pereira, 1843) While always a rarity in nature, modern technological advancements in cultivation have made the prospect of affordable Cordyceps a reality, and its assembly of potential medicinal uses continues to augment therapy and gain audience as clinical trials proceed to scientifically prove what TCM practitioners have recognized for centuries, the legendary efficacy of the Cordyceps
mushroom.

Mycological Data:

Kingdom- Fungi
Phylum- Ascomycota
Class- Ascomycetes
Order- Hypocreales
Family- Clavicipataceae
Genus- Cordyceps
Species- Cordyceps Sinensis
Basionym: Sphaeria sinensis
Synonyms: Metarhyzium,Buevaria, Isaria
Anomorphs: Cephalosporium donqchongxiacao, Cephalosporium sinensis,
Chrysosporium sinense, Hirsutella sinensis, Mortierella hepiali,
Paecilomyces hepiali, Scytalidium sp., Scytalidium hepiali,
Tolypocladium sinensis

English names: Cordyceps mushroom, Caterpillar Fungus
Japanese names: Totsu kasu, Tochukasu
Chinese names: Hia tsao tong tchong, dongchongxiacao [chongcao], …………………..(Literal translation: "winter worm, summer plant" old Chinese; modern Chinese)


Description: The ascocarp or fruitbody of the Cordyceps sinensis mushroom originates at its base on an insect larval host (usually the larva of the Himalayan bat moth, Hepialis armoricanus, although occasionally other insect hosts besides the bat moth are encountered.) and ends at the club-like cap, including the stipe and stroma. The fruitbody is dark brown to black; and the ‘root’ of the organism, the larval body pervaded by the mushroom's mycelium, appears yellowish to brown in color. The immature larvae, which forms the host upon which the Cordyceps grows, usually lives about 6 inches below ground, is ca. 10-15 mm long and has a weight of ca. 0.05 g. The infesting spores of the Cordyceps, which are thought by some mycologists to be the infectious agent for the insect, are ca. 5-10 um long. As the fungus approaches maturity, it will have consumed greater than 99 % of the infested organism, effectively mummifying the host. As the stroma matures, it will swell and develop perihelia. The average weight of an individual stroma is only ca. 0.06 g. Optimal conditions permitting; the spores are eventually discharged and taken by the wind or fall within a few centimeters of their origin.

Habitat: Cordyceps is a fungus with an annual appearance. The normal harvesting period is between the months of April and August. Fruiting off the larvae of the moths, Cordyceps thrives only at altitudes above 3,800 meters above sea level, in the cold, grassy, alpine meadows on the mountainous Himalayan Plateau of modern day Tibet, Nepal, and the modern Chinese provinces of: Sichuan, Gansu, Hubei, Zhejiang, Shanxi, Guizhon, Qinghai, and Yunnan. The caterpillar shows signs of the fungal infection underground in the spring, at which time the mycelium begins to decompose the host until fruiting is stimulated. This is after the food source (the caterpillar) has been depleted and winter gives way to the spring and summer months, when the thawing of snow at lower altitudes allows foragers to more easily find the mushroom. Whether it also fruits under the snow in the more severe months, while seeming unlikely, is at present unknown.

 
Cordyceps: Parasite or Symbiont?

Although the spore is possibly an “infectious” agent that attacks the moth larvae as some authors have advanced, it is worth noting that the entomopathogency of the Cordyceps mushroom is disputed. A growing body of logical and empirical data is suggesting to many prominent researchers that Cordyceps sinensis actually has a symbiotic relationship with the host; that the connection is mutually beneficial, rather than pathogenic. This stands to logical reason, considering the remote and inhospitable environment in which the moth/Cordyceps pairing occurs. Nature tends to select against a parasite, in that a parasite usually results in the death of the host. A more logical explanation for the unique pairing between an insect and this fungus would be that it is a mutually beneficial symbiosis, whereby the moth perhaps gains an energy boost from the Cordyceps living in it’s body, as is known to occur when other animals consume Cordyceps (Jia et al 2004). In cultivation, Cordyceps often exhibits a single celled, yeast-like anamorph growth stage. Similar yeast-like symbionts of the genus Cordyceps have been found in other insects, most logically existing to some benefit of the host insect. (Suh et al 2001) If this is the case with the Cordyceps/moth pairing, then it may be the death of the insect host that is the stressor triggering the Cordyceps to produce its fruitbody. Once the host insect dies, the Cordyceps would have to go into a reproduce-or-die mode. In most fungi, the mycelium is the stable-state life form, rather than the
more usually seen fruitbody. It is most common in the fungal kingdom that fruitbody formation does not happen unless and until some severe stressor occurs, forcing this defensive reproductive-phase response. In nature, these stressors are usually heat and cold, fire and flood, or the complete consumption of the food source and the resulting nutrient deficiency. In the laboratory it is very difficult to trigger Cordyceps to fruit, but when fruiting does occur, it is always in connection with one or more of these types of stressors.

Edibility: Not usually considered an edible mushroom due to its small size and rarity as well as its tough texture. Traditionally, Cordyceps has been consumed with a variety of meats in the form of a medicinal soup, with the type of meat used based upon the target medical condition. (Zhou et al 1998) In the medical usage of today Cordyceps is often taken with some form of vitamin C, which has been found to aid the body in its digestion and absorption of the medicinal components of the mushroom.


History and Traditional Uses

Both resilient and rare, Chinese legends and myths of this revered healing mushroom and its chameleonic characteristics span the course of millennia. The first written record of the Cordyceps mushroom comes from China, in the year AD 620, at the time of the Tang Dynasty (AD 618-AD 907), bringing substance to the once intangible allegorical narrative, which spoke of a magical creature, who's annual existence alluded to a miraculous transformation from animal to plant, in summer, and then again from plant to animal, in winter. Published works on the subject continued; Tibetan scholars wrote of the mysterious healing animal/plant through the fifteenth to eighteenth centuries, and in 1757, the earliest objective and scientifically reliable depiction of the Cordyceps mushroom was written by the author Wu-Yiluo in the Ben Cao Congxin ("New Compilation of Materia Medica"), during the Qing Dynasty.

A member of the largest subdivision of true fungi: Ascomycotina, Cordyceps finds itself amongst the most famous medicinals of the modern age; Penicillium, from which, the antibiotic penicillin is derived, the most potent hallucinogen, L.S.D., derived from the plant-parasitic ergot fungus (Claviceps purpurea), and the most highly prized and rare fungal delicacies (truffles and morels). To date, hundreds of species of Cordyceps have been identified on six continents, in a variety of habitats and with equally varied food sources.

Discovered by yak herders in the Himalayas of ancient Tibet and Nepal, nature's disclosure of the Cordyceps organism was secondhand. Recognizing the ardent behavior of their animals after grazing on Cordyceps at high altitudes in the spring, these herdsmen sought the causal agent. The cap-less mushroom they eventually found has been used in traditional Chinese medicine ever since, to treat kidney, lung, and heart ailments, male and female sexual dysfunction, fatigue, cancer, hiccups, and serious injury, to relieve pain, and the symptoms of tuberculosis and hemorrhoids, to restore general health and appetite, and to promote longevity. More potent than Ginseng and worth four times its weight in silver in ancient times. Due to its rarity, legend, and efficacy against a variety of health-related conditions, Cordyceps has held, and continues to hold, a highly esteemed position in the vast ranks of Chinese herbal remedies, which the

West has only recently begun to incorporate into officially accepted medical practices. Western descriptions of the health benefits of the Cordyceps mushroom came as early as the eighteenth century. The first such publication came from a French Jesuit priest named Perennin Jean Baptiste du Halde, who recounted his experiences with the mythical healing agent while a guest at the Emperor's court in China. Shortly after its introduction to the French scientific community, “hia tsao tong tchong” as it was then known, began to intrigue men of science and medicine. Perennin's illustration of the never-before seen association between a mushroom and an insect sparked the first Western concept of and interest in
biological pest control. However, it wasn't until 1843, that the Reverend Dr. M.J. Berkeley, having published his findings in the New York Journal of Medicine, officially defined the “root” of the Cordyceps organism, which at that time, had been taxonomized as Sphaeria sinensis. Berkley described this “root” as he called it, as that of a caterpillar, which "had been taken over almost entirely by the mushroom's mycelium". Sphaeria sinensis was not moved into the Cordyceps genus until 1878, by Pier Andrea Saccardo, who was at that time the Professor of Natural History at the University of Padua,
Illinois.


The evidence of its use as a medicinal by the Chinese-American community dates as far back as the early to mid-nineteenth century, when the Lloyd Brothers of Cincinnati, Ohio first marketed the mushroom in the United States. By the turn of the twentieth century, the Lloyd Bro’s company had become the largest producer of herbal remedies in the United States. Once a rather exclusive medicine, modern cultivation techniques have now made the mycelium of this caterpillar-borne fungus more readily available, lowering its cost on the world market and have allowed for more in-depth research into its healing potential.