827 Zuo-Yi LIU 1 , Yi-Jian YAO 2 , Zang Qi LIANG 1 , Ai-Ying LIU 1 , David N. PEGLER 2 and Mark W. CHASE 2  College of Biological Technology, Guizhou University, Guiyang 550025, Guizhou Province, People’s Republic of China.  Royal Botanical Gardens, Kew, Richmond, Surrey TW9 3AB, UK. Received 23 February 1999 ; accepted 23 October 2000. Cordyceps sinensis, the caterpillar fungus in traditional Chinese medicine, has been intensively collected from nature in recent years. As a result, the establishment of the anamorph of this species has become important for large-scale culture to meet increasing demand for medicinal use and to ease exploitation of natural populations. To establish a reliable connection between the teleomorph and anamorph stages, the ITS nrDNA sequences were sequenced from both the stroma of the telemorph and cultures of the anamorph. Observations of microcyclic conidiation were also made on germinated ascospores and compared with the anamorph in culture. Hirsutella sinensis was confirmed as the anamorph of C. sinensis by both DNA sequences and microcyclic conidiation. Two recently described species, C. multiaxialis and C. nepalensis, were shown to share identical or almost identical ITS sequences with C. sinensis. These minor variations were considered to be within the range of variation exhibited within a species, but representing different populations. Sequences from other Cordyceps species included in this study exhibited considerable differences from each other. Therefore, these three entities are probably conspecific, and the names should be regarded as synonymous. The morphological characters used in the description of the two new species are discussed. It is suggested that ITS sequences provided useful information on establishing the anamorph–telemorph connection and assisting in the delimitation of species within Cordyceps. INTRODUCTION Cordyceps sinensis (Berk.) Sacc. 1878, the caterpillar fungus, is referred to as ‘ Dong Chong Xia Cao ’ (meaning ‘ a herb in winter and a worm in summer ’) in China and ‘ Tostu Kaso ’ in Japan (Kobayasi 1941). As a traditional Chinese medicine, it is said C. sinensis was recognised 2000 years ago and formerly recorded as early as 1578 (Li 1975: 2975). In the West, the species had a number of common spellings, such as ‘ Hia Tsao Tong Tchong ’ from the Chinese by Reaumur in 1726 (Berkeley 1843) and mentioned ten years later by Du halde (1736 : 41), and ‘ Hea Tsaon Tsong Chung ’ (Westwood 1842). Its scientific name Sphaeria sinensis, however, was first given in 1843 (Berkeley 1843, Pegler et al. 1994). Saccardo (1878) transferred the species to Cordyceps as C. sinensis. Cordyceps sinensis is widely distributed in the alpine regions of south-west China including Yunnan, Gansu, Qinghai, Tibet and Sichan. Some specimens maintained in the herbarium of the Royal Botanic Gardens at Kew, were collected from Nepal and Bhutan. A few recently described species from China, similar to C. sinensis in appearance, include C. gansuensis (Zhang, Wang & Yan 1989), C. crassispora (Zang, Yang & Li 1990) and C. kangdingensis, C. nepalensis and C. multiaxialis (Zang & Kinjo 1998). At a time when teleomorph resources are seriously declining, many mycologists are studying the isolation and culture of the anamorph of C. sinensis because of its economic value as a Chinese medicine. Kobayasi (1982) reported the first culture, Stachybotrys sp., that he considered to be the anamorph of C. sinensis. Several conidial forms have subsequently been reported as possible anamorphs of C. sinensis. These include Paecilomyces sinensis (Chen & Xiao 1984), Scytalidium hepiali (Li & Ling, 1988), Tolypocladium sinensis (Li 1988), Chrysosporium sinensis (Liang 1991 a), Hirsutella sinensis (Liu et al. 1989), Synnematium sinensis (Yin & Shen 1990) and Cephalosporium sp. (Shen, Ceng & Zhang 1983). However, it may be improbable that a species such as C. sinensis can have so many different anamorphs belonging to such taxonomically different genera. Liang (1991 b) reviewed several methods available to establish anamorph–teleomorph connections in Cordyceps. He considered microcycle coni- diation, or short life-cycle, based on the direct observation of teleomorphic states developing into anamorphic states or vice versa as the most effective. Although this approach can be applied to C. sinensis, its use is very limited for other species. The development of molecular biological techniques has made it possible to extract and analyse fungal DNA even from dead fungi and to infer reliable anamorph–teleomorph connections (Egger & Sigler 1992). Vogler & Bruns (1992) resolved anamorph–teleomorph relationships in Cronartium by using internal transcribed spacers (ITS) sequence analysis. Some molecular studies have also been applied to Cordyceps Mycol. Res. 105 (7) : 827–832 (July 2001). Printed in the United Kingdom. Molecular evidence for the anamorph–teleomorph connection in Cordyceps sinensis