The principal intention of this work is to report the biodiversity of pyrenomycetous fungi habitising the state of Rajasthan. Biodiversity, the variety of life forms, of any nation is its national wealth and it is our duty to know and protect it. Fungi constitute a very large group of organisms, which are quite different from plants and animals and recognised as separate kingdom. Members of fungi found in virtually every ecological niche. Within fungi, the sac fungi, technically called as Ascomycetes form the largest phylum within fungi, which are specific in having diverse type of fruiting bodies, asci and ascospores. The pyrenomycetous ascomycetes have perithecial ascocarp and unitunicate asci with different types of ascospores.

Rajasthan state represents diverse conditions of environment, some of which are peculiar to this state and distinct from other parts of country. At western end, there is Mount Abu, only hill station in Rajasthan, which is the most humid with 1400 mm as highest average annual rainfall and at the other end there is desert area of Barmer and Jaisalmer with 100-200 mm average annual rainfall. The temperature also shows great range of variations from minimum touches the freezing point and sometimes goes below it in December and January while the maximum reaches to 48° C in months of May and June in other parts.

It is general thinking that fungi prefer humid and cold conditions but a large number of fungal formes are reported from Rajasthan which has dry and hot conditions in most of the parts at most of the times. It was fascinating to observe variously shaped fruiting bodies in the field and it gives great pleasure to observed variously coloured ascospores under microspores. These not only show the diversity but also help to study various phenomenons related to living ones and their reactions to environmental stresses.

This book is not the compilation of work and reports of other scientists but is the result of periodical regular surveys and collections of specimens from diverse parts for five years from 1997 to 2002 by us. A list of characters with description is provided for the benefit of users. All the illustrations have original photographs and drawing. A key for identification is also provided.