International Journal of Medicinal Mushrooms, 13(6): 565–581 (2011) 565 1521-1437/11/$35.00 © 2011 Begell House, Inc. www.begellhouse.com Growth and Cultural-Morphological Characteristics of Vegetative Mycelia of Medicinal Caterpillar Fungus Ophiocordyceps sinensis G.H. Sung et al. (Ascomycetes) Isolates from Tibetan Plateau (P.R. China) Gayane S. Barseghyan, 1 * John C. Holliday, 2 Thomas C. Price, 2 Leah M. Madison, 2 & Solomon P. Wasser 1,3 1 Institute of Evolution and Department of Evolutionary & Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mt. Carmel, Haifa 31905, Israel; 2 Aloha Medicinals Inc., 2300 Arrowhead Dr., Carson City, NV 89706, USA; 3 M.G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine, 2 Tereshchenkivska St., Kiev 01601, Ukraine *Address all correspondence to: Gayane S. Barseghyan, Institute of Evolution and Department of Evolutionary & Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mt. Carmel, Haifa 31905, Israel; Fax: +972 (04) 8288649; gbarseghyan@gmail.com. ABSTRACT: The morphological and cultural characteristics of vegetative mycelia of 29 Tibetan strains of medicinal caterpillar fungus Ophiocordyceps sinensis (= Cordyceps sinensis) were studied. Data on mycelial growth of the above-mentioned fungi strains on different types of nutrients, the macro- and micromorphological description of colonies grown on different agar media, and anamorph stage identiication are provided. It was shown that strains of O. sinensis demonstrated moderately slow growth on selected nutrients compared with other ascomycetous fungi. The highest growth rate value from all analyzed strains is O. sinenis N14—2.7 mm/day was completed with a mycelial run on potato-dextrose agar (pH = 6.0) in 15 d. Most of the examined strains preferred Sabouraun’s dextrose agar; some of the strains preferred potato-dextrose agar as the medium for optimal development. The least favorable nutrient for all strains was Czapek solution agar. Analyses of morphological and microstructural peculiarities on different types of nutrients were conducted and detailed descriptions and illustrations were provided. Based on macro- and micromorphological characteristics, the investigated strains were identiied as Hirsutella sinensis and Tolypocladium sinensis species, which were identiied as the anamorphs of Ophiocordyceps sinensis. KEY WORDS: anamorphs, caterpillar fungus, cultural characteristics, growth rate, Hyphomycetes, medicinal mush- room, Ophiocordyceps, Tibet ABBREVIATIONS: CFA: cat food agar; CZA: Czapek solution agar; G R : growth rate; ITS: internal transcribed spacer; KOH: potassium hydroxide solution; PDA: potato-dextrose agar; R: radius of the colony; SAB: Sabouraud’s dextrose agar with yeast extract; t: time, t: temperature; TCM: traditional Chinese medicine I. INTRODUCTION The caterpillar fungus Ophiocordyceps sinensis G.H. Sung et al. (= Cordyceps sinensis (Berk.) Sacc.), Ophiocordycepitaceae, Ascomycetes, 1 is the rarest medicinal fungus of traditional Chi- nese medicine (TCM). The fruiting bodies of O. sinensis, which produce the active medicinal in- gredients, have a rich and interesting history. For generations, O. sinensis has been considered as the premier herbal medicine in the Chinese culture for restoring energy, promoting longevity, and improv- ing the quality of life. In China, it is well known as “Dong Chong Xia Cao” (“summer grass, winter worm”), and abbreviated as “Chongcao” (“grass- worm”). Its irst documented record dates back to the 15 th century in Tibet under the name “Yartsa Gunbu” (worm in the winter and grass in the sum- mer) or simply “Bu,” and “Tochukaso” in Japan. In Nepal, Bhutan, and India, it is popularly known as “Yartsagumba,” “Yartsa Goenbub,” and “Keera Jhar,” respectively. 2–6 The species was irst described by Berkeley 7 as